MVISION Insights: TA551 Threat Group Uses Malicious Documents to Drop TrickBot and BazarLoader
Technical Articles ID:
KB95151
Last Modified: 1/14/2022
Last Modified: 1/14/2022
Environment
IMPORTANT: This Knowledge Base article discusses a specific threat that is being automatically tracked by MVISION Insights technology. The content is intended for use by MVISION Insights users, but is provided for general knowledge to all customers. Contact us for more information about MVISION Insights.
Summary
The TA551 threat group targeted entities with malicious documents attached to spam emails. An HTA file was dropped after the victim opened the document and enabled macros. The final payload were variants from the TrickBot or BazarLoader malware families. Regsvr32, MSHTA, and obfuscation were used for defense evasion while the ipconfig.exe, net.exe, and nltest.exe command line tools were used to gather sensitive information.
The McAfee Enterprise ATR Team gathers and analyzes information from multiple open and closed sources before disseminating intelligence reports.
This campaign was researched by AhnLab and shared publicly here and here.
How to use this article:
- If a Threat Hunting table has been created, use the rules contained to search for malware related to this campaign.
- Review the product detection table and confirm that your environment is at least on the specified content version.
To download the latest content versions, go to the Security Updates page. - Scroll down and review the "Product Countermeasures" section of this article. Consider implementing them if they are not already in place.
- Review
KB91836 - Countermeasures for entry vector threats . - Review KB87843 - Dynamic Application Containment rules and best practices.
- Review KB82925 - Identify what rule corresponds to an Adaptive Threat Protection and Threat Intelligence Exchange event.
Threat Hunting:
| YARA | rule SUSP_EnableContent_String_Gen { meta: description = "Detects suspicious string that asks to enable active content in Office Doc" author = "Florian Roth" reference = "Internal Research" date = "2019-02-12" hash1 = "525ba2c8d35f6972ac8fcec8081ae35f6fe8119500be20a4113900fe57d6a0de" strings: $e1 = "Enable Editing" fullword ascii $e2 = "Enable Content" fullword ascii $e3 = "Enable editing" fullword ascii $e4 = "Enable content" fullword ascii condition: uint16(0) == 0xcfd0 and ( $e1 in (0..3000) or $e2 in (0..3000) or $e3 in (0..3000) or $e4 in (0..3000) or 2 of them ) } |
This Knowledge Base article discusses a specific threat that is being tracked. The list of IOCs will change over time; check MVISION Insights for the latest IOCs.
Campaign IOC
| Type | Value |
| SHA256 | DDDCC267CE697C5EC06AACDAF884D2ECED853E987AEF4767472D491DB9903258 |
| SHA256 | 95B98956227A62FF4D290F302C81A095FD6C2FEDFD9B15CD7150FBE16F292CF2 |
| SHA256 | D500EE06ED8664BCD5ACFAC596094AED9FE9C97C4B2B21B3B052C1EB7980A8B7 |
| SHA256 | D7847C5D6C978EB21740A2C829C08DDE017C137840A8006F0720BCAF613B83FB |
| SHA256 | 73854ADE2C5247DBAAF5C6BE29C58F57BA72DB762109E635DC5DF470A37E4A8F |
| SHA256 | 45B0DBD738407CF31AD40085AE3B21CB6A924963E8F058694653ECD47011545A |
| SHA256 | 31A940DAB7BCE1146E29E59A348F2AA15FA1B30BC28ED300F6DB8A28DF1B0778 |
| SHA256 | 014DD0D9152278ED04C4AFC593EB53650FF8D06C8349F59E16C109A2106E725E |
| SHA256 | 9263854ABE5DBE018D02D6DCD445F0346B291C7FE0153AAF5E62A03B3C6DEFE7 |
| SHA256 | 9245F425794258F8E0A50F43E5DD0208034C848C355ED9CF9328B1A723405EBF |
| SHA256 | 274050578FE51120D14BB6B9DFA84E6B96A040306433886740FE12F2B5CB8B13 |
| SHA256 | 04FDB0FDC76D11ADAB9864AA36D4B54E40823FF00373B236808E47B8465A626E |
| URL | http://championriced.com |
| URL | http://app.bighomegl.at |
| URL | http://beltmorgand.com |
| URL | http://entiredelivery2014b.com |
| URL | http://povertymanagement2018b.com |
Minimum Content Versions:
| Content Type | Version |
| V2 DAT (VirusScan Enterprise) | 10099 |
| V3 DAT (Endpoint Security) | 4551 |
Detection Summary
| IOC | Scanner | Detection |
| DDDCC267CE697C5EC06AACDAF884D2ECED853E987AEF4767472D491DB9903258 | AVEngine V2 | HTML/Downloader.bg |
| AVEngine V3 | HTML/Downloader.bg | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 95B98956227A62FF4D290F302C81A095FD6C2FEDFD9B15CD7150FBE16F292CF2 | AVEngine V2 | W97M/Downloader.dkf |
| AVEngine V3 | W97M/Downloader.dkf | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| D500EE06ED8664BCD5ACFAC596094AED9FE9C97C4B2B21B3B052C1EB7980A8B7 | AVEngine V2 | W97M/Downloader.dkf |
| AVEngine V3 | W97M/Downloader.dkf | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| D7847C5D6C978EB21740A2C829C08DDE017C137840A8006F0720BCAF613B83FB | AVEngine V2 | Trojan-FTSS!2478032EDED8 |
| AVEngine V3 | Trojan-FTSS!2478032EDED8 | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 73854ADE2C5247DBAAF5C6BE29C58F57BA72DB762109E635DC5DF470A37E4A8F | AVEngine V2 | HTML/Downloader.bg |
| AVEngine V3 | HTML/Downloader.bg | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 45B0DBD738407CF31AD40085AE3B21CB6A924963E8F058694653ECD47011545A | AVEngine V2 | X97M/Downloader.kt |
| AVEngine V3 | X97M/Downloader.kt | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 31A940DAB7BCE1146E29E59A348F2AA15FA1B30BC28ED300F6DB8A28DF1B0778 | AVEngine V2 | Trojan-FTSS!EBDA58CE6041 |
| AVEngine V3 | Trojan-FTSS!EBDA58CE6041 | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 014DD0D9152278ED04C4AFC593EB53650FF8D06C8349F59E16C109A2106E725E | AVEngine V2 | X97M/Downloader.kt |
| AVEngine V3 | X97M/Downloader.kt | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 9263854ABE5DBE018D02D6DCD445F0346B291C7FE0153AAF5E62A03B3C6DEFE7 | AVEngine V2 | W97M/Downloader.dkf |
| AVEngine V3 | W97M/Downloader.dkf | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 9245F425794258F8E0A50F43E5DD0208034C848C355ED9CF9328B1A723405EBF | AVEngine V2 | W97M/Downloader.dkf |
| AVEngine V3 | W97M/Downloader.dkf | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 274050578FE51120D14BB6B9DFA84E6B96A040306433886740FE12F2B5CB8B13 | AVEngine V2 | X97M/Downloader.kt |
| AVEngine V3 | X97M/Downloader.kt | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
| IOC | Scanner | Detection |
| 04FDB0FDC76D11ADAB9864AA36D4B54E40823FF00373B236808E47B8465A626E | AVEngine V2 | W97M/Downloader.dkf |
| AVEngine V3 | W97M/Downloader.dkf | |
| JTI (ATP Rules) | - | |
| RP Static | - | |
| RP Dynamic | - |
Aggressive
IMPORTANT: Always follow best practices when you enable new rules and signatures.
When you implement new rules or signatures, always set them to Report mode first and check the alerts generated. Resolve any issues that arise and then set the rules to Block. This step mitigates against triggering false positives and allows you to refine your configuration.
For more information, see KB87843 - List of and best practices for Endpoint Security Dynamic Application Containment rules.
Virusscan Enterprise - Access Protection Rules:
Prevent programs registering as a service
