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The link “Check” led to a Google Docs page, which contained a link that redirected to a ZIP file. The ZIP file was hosted on a likely compromised SharePoint account and contained Domenus VBS, which downloads Harpy from https[:]//fashionableeder[.]com/info. At one victim, CARBON SPIDER subsequently deployed the aforementioned custom PS Sekur stager and profiled the Active Directory environment using the utility ADFind | ['T1204.001'] |
1) Cannon gathers system information and saves it to a file named ini. The Trojan sends an email to sahro.bella7[at]post.cz with i.ini as the attachment, S_inf within the body and a subject with a unique system identifier via SMTPS from one of the following accounts: Bishtr.cam47 Lobrek.chizh Cervot.woprov 2) Bishtr.cam47 3) Lobrek.chizh 4) Cervot.woprov | ['T1082'] |
Additionally, the website utilizes an AI-based application that runs in the background and optimizes its accessibility level constantly. This application remediates the website’s HTML, adapts its functionality and behavior for screen-readers used by blind users, and for keyboard functions used by individuals with motor impairments | ['T1095'] |
ESTSecurity inspected a malicious lure document discussing North Korean defectors. This lure document contained a UPX packed binary that reached out to wave[.]posadadesantiago[.]com. Based upon their report we believe SHA256: 252d1b7a379f97fddd691880c1cf93eaeb2a5e5572e92a25240b75953c88736c, either is or is strikingly similar to the document discussed in their blog post based on these similarities | ['T1566.001'] |
The xmrig mining process joins the supportxmr mining pool using the wallet address 428uyvSqdpVZL7HHgpj2T5SpasCcoHZNTTzE3Lz2H5ZkiMzqayy19sYDcBGDCjoWbTfLBnc3tc9rG4Y8gXQ8fJiP5tqeBda. At the time of writing, the malware campaign has ~25.05 KH/s hashing power and there is 11 XMR (~$1,500) in the wallet | ['T1496'] |
The primary goal of the Dark Halo threat actor was to obtain the e-mails of specific individuals at the think tank. This included a handful of select executives, policy experts, and the IT staff at the organization. Volexity notes its investigations are directly related to the FireEye report based on overlap between command-and-control (C2) domains and other related indicators such as a backdoored server running SolarWinds Orion | ['T1114.002'] |
Finally, it creates and runs a shell script at /tmp/.server.sh, which also establishes a reverse shell | ['T1059.003', 'T1059.004'] |
As with campaigns attributed to BlackEnergy group the attackers used spearphishing emails with Microsoft Excel documents attached that contain malicious macros as an initial infection vector. This time malicious documents don’t have any content with social engineering directing potential victims to click an Enable Content button | ['T1566.001'] |
1) The infection chain used in this attack begins with a weaponized link to a Google Drive folder, obfuscated using the goo.gl link shortening service. 2) When contacted, the Google Drive link retrieves a zip file, which contains a .lnk file obfuscated as a .pdf file using the double extension trick. MUSTANG PANDA has previously used the observed microblogging site to host malicious PowerShell scripts and Microsoft Office documents in targeted attacks on Mongolia-focused NGOs. 4) The .lnk file uses an embedded VBScript component to retrieve a decoy PDF file and a PowerShell script from the adversary-controlled web page. 5) The PowerShell script creates a Cobalt Strike stager payload. This PowerShell script also retrieves an XOR-encoded Cobalt Strike beacon payload from an adversary-controlled domain. 6) The Cobalt Strike Beacon implant beacons to the command-and-control (C2) IP address, which is used to remotely control the implant | ['T1027'] |
When executing the code, the browser creates an invisible image tag and sets the URL to an attack server using the file:// protocol scheme. On Windows machines, this triggers a request to a remote server via the Samba networking protocol (SMB) that also transmits the user’s login NTLM hash. These hashes can be cracked to retrieve the original login password by methods of brute-force, dictionary, or rainbow table lookups | ['T1003.004', 'T1552.001', 'T1555.003', 'T1003.005', 'T1555', 'T1003.001'] |
The ProgramArguments tell us where GrowlHelper is installed and that it takes at least one command line argument (-f). The RunAtLoad key confirms the implant will run every time the user logs in. To get an overview of the installation process, we can monitor file system activity for GrowlHelper events | ['T1546.004'] |
TrickBot has arguably been one of the most popular Trojans for the past couple of years, used by threat actors mostly because of its modular design and highly resilient infrastructure. Bitdefender researchers even analyzed one of its modules earlier this year, particularly because it targeted telecom, education, and financial services in the US and Hong Kong | ['T1090.002'] |
When executed, BoomBox ensures that a directory named NV is present in its current working directory; otherwise it terminates. If the directory is present, BoomBox displays the contents of the NV directory in a new Windows Explorer window (leaving it up to the user to open the PDF file | ['T1480', 'T1083', 'T1480', 'T1480'] |
Like many other phishing attacks, in this phishing campaign, Charming Kitten uses a fake SMS (Figure 1) to trick their victims. They send confirmation messages stating ‘Google Account Recovery’ to their targets; they claim these messages are sent by Google and the user must follow the link in the SMS to confirm the identity | ['T1598.003'] |
Viewing results Commands scheduled with at run as background processes. Output is not displayed on the computer screen. To redirect output to a file, use the redirection symbol (>). If you redirect output to a file, you need to use the escape symbol (^) before the redirection symbol, whether you are using at at the command line or in a batch file. For example, to redirect output to Output.text, type: at 14:45 c:\test.bat ^>c:\output.txt The current directory for the executing command is the systemroot folder. Changing system time If you change the system time at a computer after you schedule a command to run with at, synchronize the at scheduler with the revised system time by typing at without command-line options. Storing commands Scheduled commands are stored in the registry. As a result, you do not lose scheduled tasks if you restart the Schedule service. Connecting to network drives Do not use a redirected drive for scheduled jobs that access the network. The Schedule service might not be able to access the redirected drive, or the redirected drive might not be present if a different user is logged on at the time the scheduled task runs. Instead, use UNC paths for scheduled jobs | ['T1053.002'] |
BUBBLEWRAP is a full-featured backdoor that is set to run when the system boots, and can communicate using HTTP, HTTPS, or a SOCKS proxy | ['T1071.001'] |
BITSAdmin is a command-line tool that you can use to create download or upload jobs and monitor their progress. For full, comprehensive documentation of the tool and all of its commands, see bitsadmin and bitsadmin examples in the Windows IT Pro Center | ['T1105'] |
Once the malware starts it tries to reach a hardcoded C2. The communication takes place using the unmodified HTTP-based protocol, the request and response body are RC4-encrypted, and the encryption key is also hardcoded into the sample. As the result of the RC4 encryption may contain binary data, the malware additionally encodes it in BASE64, to match the HTTP specification | ['T1071.001'] |
TG-3390 uses DLL side loading, a technique that involves running a legitimate, typically digitally signed, program that loads a malicious DLL. The DLL acts as a stub loader, which loads and executes the shell code. The adversaries have used this technique to allow PlugX and HttpBrowser to persist on a system | ['T1574.002'] |
1) User must open the Microsoft Word email attachment 2) User must scroll to page three of the document, which will run the DealersChoice Flash object 3) The Flash object must contact an active C2 server to download an additional Flash object containing exploit code 4) The initial Flash object must contact the same C2 server to download a secondary payload 5) Victim host must have a vulnerable version of Flash installed | ['T1203'] |
This agent also built in a function aptly named “DeleteLeftovers,” to remove certain artifacts of the attack | ['T1070'] |
In addition to the aforementioned DOCX file, we found another related DDE enabled document based on an infrastructure overlap with a Zebrocy C2 IP address. This related delivery document was an RTF file that downloaded and installed a payload used to load the open-source Koadic tool. We do not have telemetry on the target or attack vector, but we know the RTF file used DDE to download and execute an executable that loaded Koadic. We believe the actor used a cryptor on the payload, as it obtains a filename and script from within its resources and decodes these resources by multiplying each byte by negative one. The payload then uses the MD5 hash (14331d289e737093994395d3fc412afc) of what appears to be a hardcoded SHA1 hash (B6A75B1EF701710D7AEADE0FE93DE8477F3BD506) as an RC4 key to decrypts the resulting decoded data. The embedded VBScript is retrieved from a resource and decrypted using the same algorithm as discussed above, which results in the following cleartext | ['T1140'] |
Impersonation using Kerberos pass-the-ticket attacks (Mimikatz PowerShell) - Email extraction from the MS Exchange Server using compromised credentials - Archiving sensitive information - Data exfiltration via legitimate cloud services - Secure file deletion | ['T1059.001', 'T1550.003', 'T1114.002', 'T1078'] |
Computer name - System info using: cmd /c systeminfo >%temp%\temp.ini - List of currently running process using: cmd /c tasklist >%temp%\temp.ini | ['T1082'] |
Different drivers will be loaded based on the system version. The malware uses IsWow64Process to determine which driver version to load. These drivers are stored in the resource section of the binary and are compressed with the Lempel-Ziv algorithm. The driver file is written to system32\drivers with a 4-character, pseudo-randomly generated name. This file is then decompressed using LZCopy to a new file with a “.sys” extension | ['T1027', 'T1140'] |
The main purpose of P8RAT is downloading and executing payloads (consisting of PE and shellcode) from its C2 server | ['T1001.001'] |
Throughout 2017 and 2018 Unit 42 has been tracking and observing a series of highly targeted attacks focused in South East Asia, building on our research into the KHRAT Trojan. Based on the evidence, these attacks appear to be conducted by the same set of attackers using previously unknown malware families. In addition, these attacks appear to be highly targeted in their distribution of the malware used, as well as the targets chosen. We believe this group is previously unidentified and therefore have we have dubbed it “RANCOR”. The Rancor group’s attacks use two primary malware families which we describe in depth later in this blog and are naming DDKONG and PLAINTEE. DDKONG is used throughout the campaign and PLAINTEE appears to be new addition to these attackers’ toolkit. Countries Unit 42 has identified as targeted by Rancor with these malware families include, but are not limited to | ['T1059.005', 'T1105'] |
To avoid detection, the macros employ simple obfuscation of interesting strings that ultimately just used base64 encoding. However, it used a somewhat unusual method where it would first convert the base64-encoded text into hex, and then convert that hex into a text string | ['T1027'] |
Some additional log file analysis reveals that a dotm file hosted with a. jpg extension was accessed by an Israeli IP address. This IP address likely belongs to a victim in Israel that executed the main DOCX. Based on the analysis of the user-agent string belonging to the Israel IP address Microsoft+Office+Existence+Discovery indicates that the dotm file in question was downloaded from within Microsoft Office (template injection | ['T1480'] |
1) It uses the application programming interface (API) CreateFileA to \\.\PHYSICALDRIVE0 to retrieve the handle of the hard disk. 2) It overwrites the first sector of the disk (512 bytes) with "0x00". The first sector is the disk’s MBR. 3) It will try to perform the routines above (steps 1-2) on \\.\PHYSICALDRIVE1, \\.\PHYSICALDRIVE2, \\.\PHYSICALDRIVE3, and so on, as long as a hard disk is available | ['T1082'] |
Upon further inspection, Kroll learned that an employee using their work computer had clicked on a malicious link from their personal email account that downloaded a Qakbot dropper | ['T1059.005'] |
This activity has TTP and targeting overlap with previous activity, suspected to be APT29. The 2018 and 2016 LNK files are similar in structure and code, and contain significant metadata overlap, including the MAC address of the system on which the LNK was created | ['T1204.001', 'T1566.001'] |
APT19 used three different techniques to attempt to compromise targets. Toward the end of May, APT19 switched to using macro-enabled Microsoft Excel (XLSM) documents. In the most recent versions, APT19 added an application whitelisting bypass to the XLSM documents | ['T1218.010'] |
WastedLocker aims to encrypt the files of the infected host. However before the encryption procedure runs, WastedLocker performs a few other tasks to ensure the ransomware will run properly | ['T1574.001'] |
Attempted to blend in with a file name that matched the system name it resided on - Configured for WMI persistence (generally uncommon in 2019) - Used likely compromised infrastructure for C2 - Masquerades its command-and-control (C2) traffic as legitimate Google Notifications HTTP requests | ['T1071.001', 'T1001'] |
In most systems compromised by Kobalos, the SSH client is compromised to steal credentials. This credential stealer is unlike any of the malicious OpenSSH clients we’ve seen before, and we’ve looked at tens of them in the past eight years. The sophistication of this component is not the same as Kobalos itself: there was no effort to obfuscate early variants of the credential stealer. However, we found newer variants that contain some obfuscation and the ability to exfiltrate credentials over the network | ['T1048'] |
The C2 server can also send a PowerShell command to capture and store a screenshot of a victim’s system. POWRUNER will send the captured screenshot image file to the C2 server if the “fileupload” command is issued. Figure 6 shows the PowerShell “Get-Screenshot” function sent by the C2 server | ['T1113'] |
At installation, the MSI file drops three files and creates one hidden directory (UFile) into C:\ProgramData\Apple\Update\, likely as a ruse | ['T1564.001', 'T1564.001'] |
On execution, the MSI downloader starts by checking if it is running in a virtual machine. If not, downloads a zip file, unzips it, deletes itself, establishes persistency and restarts the system | ['T1140', 'T1102.003'] |
ServHelper’s payload, an NSIS Installer signed with a valid digital signature (further details on the certificate ahead), is downloaded by msiexec.exe to its temporary folder (C:\Windows\Installer\MSI[4-charachter-string].tmp) and executed | ['T1218.007'] |
secretsdump.py: Performs various techniques to dump secrets from the remote machine without executing any agent there. For DIT files, we dump NTLM hashes, Plaintext credentials (if available) and Kerberos keys using the DL_DRSGetNCChanges() method. It can also dump NTDS.dit via vssadmin executed with the smbexec/wmiexec approach. mimikatz.py: Mini shell to control a remote mimikatz RPC server developed by @gentilkiwi | ['T1003.004', 'T1003.002', 'T1003.003', 'T1003.001'] |
To recap, on September 18, 2017, we disclosed that CCleaner had been targeted by cybercriminals, in order to distribute malware via the CCleaner installation file. The altered installation file was downloaded by 2.27 million CCleaner customers worldwide. The malware was introduced to the build server of Piriform, the company developing CCleaner, some time between March 11 and July 4, 2017, prior to Avast’s acquisition of Piriform on July 18, 2017 | ['T1195.002'] |
These credentials are used in a credential stuffing or password spraying attack against the victim’s remote services, such as webmail or other internet reachable mail services. After obtaining a valid account, they use this account to access the victim’s VPN, Citrix or another remote service that allows access to the network of the victim. Information regarding these remotes services is taken from the mailbox, cloud drive, or other cloud resources accessible by the compromised account. As soon as they have a foothold on a system (also known as patient zero or index case), they check the permissions of the account on that system, and attempt to obtain a list of accounts with administrator privileges. With this list of administrator-accounts, the adversary performs another password spraying attack until a valid admin account is compromised. From here on the adversary stops using the victim’s remote service to access the victim’s network, and starts using the Cobalt Strike beacon for remote access and command and control | ['T1082'] |
This dynamic link library appears to be a legitimate version of libcurl.dll except for a single exported function, which is referred to as ordinal #52 and curl_share_init in the analyzed sample. This function has been modified by threat actors to extract a resource contained within libcurl.dll, decrypt malicious data included in that resource, and load the resulting DLL to execute a malicious function. When this function is executed, the SodomNormal communications module begins running within Libcurl.dll | ['T1140'] |
Wscript.exe does a number of things: It deletes the original QakBot.vbs and writes four files to disk in %APPDATA% induce.flac, pep.csv, rhythm.tex and senate.m4a. Senate.m4a is deleted after full process execution | ['T1070.004'] |
These privilege escalation modules are the ones we caught when we queried for Jian’s global configuration table. We also found a couple of more Local Privilege Escalation exploits from the NtElevation series | ['T1068'] |
First, several of these commands contain checks to determine the environment in order to use appropriate paths or commands. The ‘tasklist’ command will use a WMI query or the “ps” command, which allows Kazuar to obtain running processes from both Windows and Unix systems. Also, Kazuar’s ‘cmd’ command will run commands using “cmd.exe” for Windows systems and “/bin/bash” for Unix systems. These two commands provide evidence that the authors of Kazuar intended to use this malware as a cross-platform tool to target both Windows and Unix systems | ['T1059.003'] |
All the commands received from the C2 are first saved to an auxiliary file and then stored encrypted in the system registry. The standalone thread will decrypt and execute them | ['T1059.003', 'T1047'] |
sifo – Collect victim system information - drive – List drives on victim machine - list – List file information for provided directory - upload – Upload a file to the victim machine - open – Spawn a command shell | ['T1082', 'T1083', 'T1105', 'T1082', 'T1083'] |
The buffer containing the ZxShell Dll in the new location is freed using the VirtualFree API function. A handle to the DLL file is taken in order to make its deletion more difficult. The ZxShell mutex is created named @_ZXSHELL_ | ['T1218.011'] |
Use of Open Source Tools In an attempt to avoid detection and as an anti-analysis tactic, the OilRig group abused an open source tool called Invoke-Obfuscation to obfuscate the code used for QUADAGENT. Invoke-Obfuscation is freely available via a Github repository and allows a user to change the visual representation of a PowerShell script simply by selecting the desired obfuscation techniques. Invoke-Obfuscation offers a variety of obfuscation techniques, and by analyzing the script we were able to ascertain the specific options in this attack. After identifying the specific options used to obfuscate QUADAGENT, we were able to deobfuscate the PowerShell script and perform additional analysis. We found two obfuscation techniques applied to the script: the first one changing the representation of variables; the second one changing the representation of strings in the script. Invoke-Obfuscation calls the string obfuscation used by the actors to further obfuscate this script Reorder, which uses the string formatting functionality within PowerShell to reconstruct strings from out of order substrings (ex. 1}{0}" -f 'bar','foo'). During our analysis, we installed Invoke-Obfuscation and used it to obfuscate a previously collected QUADAGENT sample to confirm our analysis | ['T1059.001'] |
Further into the infection process, the malware chooses a service name randomly from netsvc in order to use it for the payload creation path. The malware then creates a file named bcdbootinfo.tlp in the system folder containing the infection time and the random service name that is chosen. We’ve discovered that the malware operator checks this file to see whether the remote host was infected and, if so, when the infection happened | ['T1547.001'] |
Between August 2 and 4, the actor sent targeted spearphishing emails containing malicious URLs linking to documents to multiple defense contractors | ['T1204.001'] |
The module gathers information about the user and attempts to verify whether this is a local admin or a domain admin. This shows that after infecting the machine, Valak chooses to target mainly administrators and domain admins. This indicates a propensity to target higher profile accounts such as enterprise admins | ['T1087.001', 'T1087.002'] |
The initial routine decrypts selected parts of the code section using XOR with a hardcoded value | ['T1027'] |
A second method consists to use the CredEnumerateW Windows API. Finally, Perfc.dat contains three embedded executables in its resource section which are compressed with zlib. Two of the executables are used to recover user credentials (32 and 64 bits) while the third one is the PsExec binary | ['T1021.002'] |
It can download and execute arbitrary code provided from the C&C server, as well as maintain a virtual file system (VFS) inside the registry. The VFS, and any additional files created by the code, are encrypted and stored in a location unique to each victim | ['T1027'] |
In June 2015, a number of web portal email accounts were hacked, sending emails with malicious Hangul document files and phishing emails to steal portal account credentials. In January 2016, a large number of emails with malicious attachments were sent under the guise of ‘Office of National Security at the Blue House’ to government research institutes. Analysis by related organizations identified the malicious attachment as Kimsuky malware [3 | ['T1586.002'] |
Both malicious programs share the code for LZMA compression algorithm. In CloudAtlas it is used to compress the logs and to decompress the decrypted payload from the C&C servers, while in Red October the “scheduler” plugin uses it to decompress executable payloads from the C&C | ['T1059.001', 'T1059.005'] |
X-Session: 0"). Its presence on a compromised system allows a threat actor to execute a wide variety of commands, including uploading and downloading files, and spawning a reverse shell. The malware can be configured to use multiple network protocols to avoid network-based detection. DLL side loading is often used to maintain persistence on the compromised system. Antivirus detection for HttpBrowser is extremely low and is typically based upon heuristic signatures. DLL side loading has been used to maintain persistence on the compromised system. More information about HttpBrowser is available in Appendix B. HttpBrowser URI. Source: Dell SecureWorks) - ChinaChopper web shell — A web-based executable script (see Figure 4) that allows a threat actor to execute commands on the compromised system. TG-3390 has used additional web shells containing similarly formatted passwords | ['T1071.004'] |
Similar to RIPTIDE campaigns, APT12 infects target systems with HIGHTIDE using a Microsoft Word (.doc) document that exploits CVE-2012-0158. FireEye observed APT12 deliver these exploit documents via phishing emails in multiple cases. Based on past APT12 activity, we expect the threat group to continue to utilize phishing as a malware delivery method | ['T1203'] |
The screenshot in Figure 8 of the inf method within a Cannon sample (SHA256: 4405cfbf28. ) shows the information gathered that is exfiltrated to the C2 via email, specifically with RunningPlace and LogicalDrives header strings | ['T1082'] |
The second generation (2.x) was used to conduct an attack which we investigated during its active stage. We successfully prevented data transfer to the cybercriminals’ server and isolated the infected systems in the company’s local network. The incidents, as well as results of our investigation, are described in the full report on the Winnti group (PDF | ['T1014'] |
Conficker will copy itself with a random name into the system directory %systemroot%\system32 and register itself as a service. The remote computer will then download the worm from the URL given and then start to infect other machines as well. Upon successful infection, it will also patch the hole to prevent other worms to infect the machine" (Racicot | ['T1046', 'T1112'] |
On October 28, we observed APT3 sending out spearphishing messages containing a compressed executable attachment. The deflated exe was a variant of the same downloader described above and connected to 198.55.115.71 over port 1913 via SOCKS5 proxy. The secondary payload in that case was detected as Backdoor.APT.CookieCutter (aka Pirpi) and also named newnotepad.exe (MD5 8849538ef1c3471640230605c2623c67) and connected to the known APT3 domains | ['T1090.002', 'T1095'] |
You are using Microsoft Internet Explorer. We recommend using Chrome or Firefox for the best experience | ['T1059.003'] |
In addition, PLAINTEE will create a unique GUID via a call to CoCreateGuid() to be used as an identifier for the victim. The malware then proceeds to collect general system enumeration data about the infected machine and enters a loop where it will decode an embedded config blob and send an initial beacon to the C2 server. The configuration blob is encoded using a simple single-byte XOR scheme. The first byte of the string is used as the XOR key to in turn decode the remainder of the data | ['T1573.001'] |
We named Lazarus the most active group of 2020. We’ve observed numerous activities by this notorious APT group targeting various industries. The group has changed target depending on the primary objective. Google TAG has recently published a post about a campaign by Lazarus targeting security researchers. We have seen Lazarus attack various industries using this malware cluster before. In mid-2020, we realized that Lazarus was launching attacks on the defense industry using the ThreatNeedle cluster, an advanced malware cluster of Manuscrypt (a.k.a. NukeSped). While investigating this activity, we were able to observe the complete life cycle of an attack, uncovering more technical details and links to the group’s other campaigns | ['T1005', 'T1566.002', 'T1204.002'] |
Once the initial computer on the targeted organization’s network is infected with Vcrodat, Whitefly begins mapping the network and infecting further computers. The attackers rely heavily on tools such as Mimikatz to obtain credentials. Using these credentials, the attackers are able to compromise more machines on the network and, from those machines, again obtain more credentials | ['T1588.002', 'T1068'] |
The diagram below illustrates the methodology used by the actor to communicate with the FoggyWeb backdoor located on a compromised internet-facing AD FS server | ['T1071.001'] |
id — the generated unique identifier of the infected host - message — the Base64-encoded output from the newly created cmd.exe console process | ['T1027'] |
The archive contains a legitimate older version of Microsoft Word (Microsoft Word 2007) executable file that is named ‘Noi dung chi tiet don khieu nai gui cong ty.exe’ which translates to ‘Learn more about how to use your company’ in English. The attacker used the DLL side loading technique to load a malicious DLL by the older version of Microsoft Word. When opening the executable file in the archive, it loads the malicious DLL in the same directory. The DLL executes multi-stage shellcodes and each shellcode employs various technique to hide the next stage | ['T1574.002'] |
Summary In early May, Unit 42 discovered an attack campaign against at least one defense company in Russia and one unidentified organization in South Korea delivering a variant of Bisonal malware. While not previously publicly documented, the variant has been in the wild since at least 2014. There are three primary differences between it and older Bisonal malware including a different cipher and encryption for C2 communication, and a large rewrite of the code for both network communication and maintaining persistence. The adversary behind these attacks lured the targets into launching the Microsoft Windows executable malware by masquerading it as a PDF file (using a fake PDF icon) and reusing publicly available data for the decoy PDF file’s contents. Attacks using Bisonal have been blogged about in the past. We believe it is likely these tools are being used by one group of attackers. Though Bisonal malware has been in the wild for at least seven years and frequently updated, the actors keep using same high-level playbooks. Common features of attacks involving Bisonal include | ['T1105'] |
After decoding the PDF and AppleSeed payload, the content gets written into the ProgramData directory. At the end, the decoy PDF file is opened by calling Wscript.Shell.Run and the AppleSeed payload executed through PowerShell by calling regsvr32.exe. Calling regsvr32.exe to run a DLL registers it as a server that automatically calls the DLL export function that has been named DllRegisterServer | ['T1218.010'] |
To illustrate a real example of how this worked and looked to a website visitor, the following section will use one of the few pages of the fake site baomoivietnam[.]com that was designed to profile visitors and deliver malware or a phishing link. On this site, a news story (https://www.baomoivietnam[.]com/dai-hoc-ton-duc-thang-hieu-truong-lam-quyen-de-xay-ra-sai-pham/) about an investigation into potential improper conduct by a university professor in Vietnam contained malicious content. Once the page was accessed, a special OceanLotus server on the hostname cdn.arbenha[.]com would be leveraged to load malicious JavaScript to load a fake video player. At first, the page would display a dialog indicating that the video was loading (Đang tải) as shown in Figure 1 below | ['T1598.003'] |
In November 2019, when MegaCortex v4 appeared, there was a rollback of sorts, bringing the Base64 key back into play and using it to decrypt the malware’s components. The implementation was not the same as previous versions, with that Base64 key embedded into the binary and then passed to a decrypting function instead of passing it as an argument to the command-line | ['T1140'] |
The script sets up a new HTTP object and then tries to disable the system's local proxy settings | ['T1562.001'] |
Bisonal main module The DLL (pvcu.dll) is Bisonal malware but using a different cipher for C2 communication that other publicly documented samples. Booz Allen Hamilton in 2014 and AhnLab in 2015 reported on Bisonal using a simple XOR cipher to hide the C2 address strings in the body. The Bisonal sample we observed in this case employs the RC4 cipher with the key “78563412”. To date, all Bisonal samples we have seen using RC4 use this same key. The oldest sample we have dates to 2014, so this variant has been in the wild for several years. For example, the Bisonal malware in 2012 used send() and recv() APIs to communicate with its C2 | ['T1082', 'T1071.001', 'T1140'] |
When executed, QakBot will check whether it has previously been executed on the machine by checking for the specified malware folder. If QakBot discovers it is a first time run, it will relaunch itself from cmd.exe with the /C parameter that will inform the loader to proceed and run its Anti-VM checks on the machine and return the results to the parent process. If QakBot detects it is running in a VM environment, then the final payload will not be decrypted since QakBot uses the return value from these checks in its final decryption routine. Figure 7 below shows the QakBot environment check logic | ['T1057', 'T1055.012', 'T1059.003', 'T1083'] |
loaddl: a command responsible for downloading and executing additional modules using the rundll32.exe process. selfkill: a command that is responsible for self-terminating and deleting the malware from the machine | ['T1105'] |
WMI permanent event subscriptions can be used to trigger actions when specified conditions are met. Attackers often use this functionality to persist the execution of backdoors at system start up. Subscriptions consist of three core WMI classes: a Filter, a Consumer, and a FilterToConsumerBinding. WMI Consumers specify an action to be performed, including executing a command, running a script, adding an entry to a log, or sending an email. WMI Filters define conditions that will trigger a Consumer, including system startup, the execution of a program, the passing of a specified time and many others. Creating a WMI permanent event subscription requires administrative privileges on a system | ['T1546.003'] |
The RTF file contains macro codes that will execute a PowerShell command to retrieve a dynamic-link library (DLL) file before executing it using odbcconf.exe, a command-line utility related to Microsoft Data Access Components. The DLL will drop and execute a malicious JScript using regsvr32.exe, another command-line utility, to download another JScript and execute it using the same regsvr32.exe. During analysis, we received a PowerShell command that downloads Cobalt Strike from hxxps://5[.]135[.]237[.]216[/]RLxF | ['T1059.001', 'T1218.010', 'T1218.008'] |
In additional to the browsers credential stealer, Olympic Destroyer drops and executes a system stealer. The stealer attempts to obtain credentials from LSASS with a technique similar to that used by Mimikatz | ['T1555.003', 'T1003.001'] |
The SOMBRAT backdoor is packaged as a 64-bit Windows executable. It communicates with a configurable command and control (C2) server via multiple protocols, including DNS, TLS-encrypted TCP, and potentially WebSockets. The backdoor's primary purpose is to download and execute plugins provided via the C2 server. In contrast to the SOMBRAT version published in November 2020, Mandiant observed additional obfuscation and armoring to evade detection, this SOMBRAT variant has been hardened to discourage analysis. Program metadata typically included by the compiler has been stripped and strings have been inlined and encoded via XOR-based routines | ['T1095'] |
As seen in the above image, the Bazar backdoor can handle quite a few commands. This next section focuses on case 1, which retrieves various pieces of additional information on the infected machine | ['T1005'] |
2) Scan the network environment of the infected machine; checks for availability of specific ports on servers that share the same internal and external subnet mask (i.e 255.255.0.0\16). 3) Try to exploit the following Remote Code Execution vulnerabilities in the targeted servers | ['T1046'] |
Harvest cookies and a password database for supported browsers. Supports: Win7 IE, Win10 IE, Edge, Chrome, and Naver Whale - Recursively search a path and upload file metadata (timestamps, size, and full path). - Spawn a thread to recursively search a path and upload files as a ZIP archive | ['T1539'] |
A recent Lokibot campaign has been spotted, which made use of a tunneling service to spread the malware. According to My Online Security, threat actors behind this campaign leveraged a service known as Ngrok. As claimed on the website, Ngrok reveals servers in NATs and Firewalls over secure tunnels. Hence, the service acted as a direct tunnel or a VPN which the actors exploited to push the malware through spam emails | ['T1572'] |
The script itself works as a downloader for additional files needed for loading the malware into the system, which are hosted separately as a ZIP package. We confirmed two different techniques used for distributing the Melcoz backdoor: the AutoIt loader script and DLL Hijack | ['T1105'] |
The Magic Hound campaign was also discovered deploying an IRC Bot, which we have named MagicHound.Leash. We discovered this connection when we observed a DropIt sample installing a backdoor Trojan that used IRC for its C2 communications | ['T1113'] |
5) Downloads the ‘kinsing’ malware and runs it 6) Uses crontab to download and run the shell script every minute 7) Looks for other commands running in cron, and if ones were identified, deletes all cron jobs, including its own. We are not certain why the attackers chose to do so, but that is what the script executes:crontab -l || sed '/update.sh/d' || crontab | ['T1059.004', 'T1053.003'] |
Once on a victim’s PC, the dropper executable is launched and it decrypts and loads the Gh0stRAT DLL into memory. It then passes the config buffer to the extracted DLL and calls the exported function (Shellex | ['T1129'] |
The Warzone RAT can steal credentials from the Outlook and Thunderbird email clients as shown in the image below (figure 10 | ['T1555.003'] |
Emotet could be dropping malware with Remote Access Trojan (RAT) capabilities damaging the integrity of the overall network. After reviewing systems for Emotet indicators, reimage and move clean systems to a containment VLAN, segregated from the infected network. It is possible that the Outlook account may now have rules to auto-forward all emails to an external email address, which could result in a data breach. Search base64 encoded network stream data referencing the organization’s email domain. If references are found, perform additional analysis to see if a data breach has occurred | ['T1114.001'] |
Attack overview . Flagpro is used in the initial stage of attacks to investigate target’s environment, download a second stage malware and execute it. Flagpro communicates with a C&C server, and it receives commands to execute from the server, or Flagpro downloads a second stage malware and then executes it. Therefore, Flagpro may have already been used for attacking cases at that point. We call this sample using MFC as “Flagpro v2.0” and old one as “Flagpro v1.0” in this article. Once Flagpro is launched, it communicate with a C&C server and executes the received commands as shown in the above list. If it is not included in both Download Command fields in the command, Flagpro will not execute the main processes such as downloading, executing OS commands, collecting authentication information, and so on. If a Download Command field has “ExecYes”, Flagpro downloads and executes the file. In requesting commands, sending execution results of OS commands or collected authentication information, Flagpro accesses a C&C server with specific URL paths and queries. Following image is an example of the response: Detections . To detect attacks using Flagpro, it is effective to create and install custom signature both on network and endpoint devices. In addition, the investigation commands after Flagpro establishes the connection with the C&C server like following are also useful for detection | ['T1069.001'] |
Figure 5 Uploading a file to server via RGDoor Downloading a file from the server via RGDoor | ['T1105'] |
If the configuration is parsed successfully, the program writes the string "Meteor has started. to an encrypted log file, suggesting that the internal name of the malware is “Meteor“. As we will see later on in this article, another name was used in previous attacks. Throughout the entire execution of the malware, it keeps logging its actions to this same encrypted log file. Appendix C contains a helper script to decrypt the log file | ['T1105'] |
Alongside evidence of compromise of the organization itself, Symantec also found a copy of one of the company’s own files, relating to its messaging software, on a staging server used by Chafer. The file was in a directory alongside a number of hacking tools used by the attackers | ['T1005'] |
Skidmap uses fairly advanced methods to ensure that it and its components remain undetected. For instance, its use of LKM rootkits — given their capability to overwrite or modify parts of the kernel — makes it harder to clean compared to other malware. In addition, Skidmap has multiple ways to access affected machines, which allow it to reinfect systems that have been restored or cleaned up | ['T1059.004'] |
During this activity, we noticed the wiper changing the system time to August 2012, as the temporary license key for the RawDisk driver requires the system time to not exceed the month of August, which is when the temporary license would expire. This modification to the system time was seen in the previous campaign, and the temporary license key within the wiper component is the exact same as wiper component from the 2012 attacks. The wiper itself queries the following registry keys to obtain a list of partitions to overwrite | ['T1012'] |