Trojan.PS1.POWTRAN.B

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Arrival Details

This Trojan arrives on a system as a file dropped by other malware or as a file downloaded unknowingly by users when visiting malicious sites.

Installation

This Trojan drops the following files:

• %System%\WindowsPowerShell\v1.0\WinRing0x64.sys -> Allows XMRig to boost mining capability
• %System%\mue.exe

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It adds the following processes:

• If the sample is executed on Windows 10:
  • powershell -NoP -NonI -exec bypass `"`$fun='{base 64 encoded script}';`$defun=[System.Text.Encoding]::ASCII.GetString([System.Convert]::FromBase64String(`$fun));iex `$defun;`$mon = ([WmiClass] 'root\default:systemcore_Updater6').Properties['mon'].Value;`$funs = ([WmiClass] 'root\default:systemcore_Updater6').Properties['funs'].Value ;iex ([System.Text.Encoding]::ASCII.GetString([System.Convert]::FromBase64String(`$funs)));Invoke-Command -ScriptBlock `$RemoteScriptBlock -ArgumentList @(`$mon, `$mon, 'Void', 0, '', '')"
• If the sample is executed other than Windows 10:
  • powershell -NoP -NonI -W Hidden -exec bypass "$mon = ([WmiClass] 'root\default:systemcore_Updater6').Properties['mon'].Value;$funs = ([WmiClass] 'root\default:systemcore_Updater6').Properties['funs'].Value ;iex ([System.Text.Encoding]::ASCII.GetString([System.Convert]::FromBase64String($funs)));Invoke-Command -ScriptBlock $RemoteScriptBlock -ArgumentList @($mon, $mon, 'Void', 0, '', '')"
• netstat -anop tcp

Process Termination

This Trojan terminates the following processes if found running in the affected system's memory:

• powershell.exe and schtasks.exe that have an ESTABLISHED network connection via port 3333, 5555, 7777

Download Routine

This Trojan accesses the following websites to download files:

• http://{BLOCKED}bcv.net/banner
• http://{BLOCKED}kbcv.net/sync
• https://raw.{BLOCKED}usercontent.com/upinfoarch/up/master/domtar

Other Details

This Trojan does the following:

• It uses Windows Management Instrumentation (WMI) to do the following:
  • It creates the following WMI Class under root\default:
    • systemcore_Updater6
      • WMI objects:
        • mons = base-64 encoded Monero Executable
        • ring = base-64 encoded Monero module