Lab52 has detected malicious activity targeting Indonesian victims. This activity could be linked to an intelligence operation. We have been tracking this activity since December 27th of 2019
The main tools of this threat actor, are built as DLL files, and launched with this commands:
- “C:\Windows\System32\rundll32.exe” shell32.dll,ShellExec_RunDLL regsvr32 /s C:\ProgramData\pubpool.dll /i:process104.dll
- “C:\WINDOWS\system32\regsvr32.exe” /s C:\ProgramData\pubpool.dll /i:process104.dll
|process100.dll||5813497bde09577bd1adf24b02707918bb15af62||Uploaded to Virus Total Intelligence on 12-07-2019 from Indonesia.|
|runtime_report.dll||1815820307a23b99d93e7307ade8b6443bbb8e96||Uploaded to Virus Total Intelligence on 2019-07-17 12:29:35 from Indonesia.|
|process104.dll||f09176a5130c17356ad2aa5850ca14a0a02a9ded||Uploaded to Virus Total Intelligence on 2019-07-17 12:29:10 from Indonesia|
|pubpool.dll||e7b27d5e936d8dedc55ebe4ff64020d1bf4238b2||Uploaded to Virus Total Intelligence on 2019-07-17 12:29:26 from Indonesia|
Pubpool.dll is used as a loader for three more encrypted dll that have been found during the incident research:
1. pubpool.dll file
Lab52 has analyzed pubpool.dll and this component has code to decrypt and load files, working as a dll loader. In the next picture, you can see one example of a dll being decrypted by pubpool in memory:
2. process104.dll file
When we launch pubpool.dll with process104.dll as parameter, this dll maps this section:
process104.dll is decrypted and mapped as inject_usb.dll. It’s main purpose is to infect USB devices.
This library exports a function named “done”. The function can be seen in the next picture:
“Done” function checks for the existence of a mutex and starts if there isn’t another instance in execution. Inject_usb.dll creates a folder named “.Recycle Bin” in every removable device and a log file named “si.log”.
3. process100.dll file
When we launch pubpool.dll with process100.dll as a parameter, this dll maps the next sections:
process100.dll is decrypted and mapped as inject_host.dll. This module execute the malware. In the next pictures there is some IOCs:
One LNK example:
4. runtime_report.dll file
When we launch pubpool.dll with runtime_report.dll as parameter, the loader maps this section:
runtime_report.dll is decrypted and mapped as TinyMet.dll. This module deploys TinyMET, a “tiny” meterpreter stager.
This TinyMet version has a Mutex TEST_9I89JNDBPWQ9ND:
TinyMet connects to Internet using a Hardcoded domain and User-Agent that can be seen in the next picture:
- Domain: musicstore.global.ssl.fastly[.]net
- User-Agent: Mozilla/4.0 (compatible; MSIE 6.1; Windows NT)
Lab52 has the hypothesis that this infection is part of an intelligence operation. It’s a malware developed by a threat actor (currently, it’s not possible to identify the malware family). Attribution is not possible with the information handled by Lab52.