Analysis by: Nathaniel Gregory Ragasa
ALIASES:

Trojan.SuspectCRC(IKARUS)

 PLATFORM:

Windows

 OVERALL RISK RATING:
 DAMAGE POTENTIAL:
 DISTRIBUTION POTENTIAL:
 REPORTED INFECTION:
 INFORMATION EXPOSURE:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet

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.

  TECHNICAL DETAILS

File Size: 520,704 bytes
File Type: DLL
Memory Resident: No

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.

Autostart Technique

This Trojan creates the following registry entries to enable automatic execution of dropped component at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
{Random Characters} = "%System%\rundll32.exe\" "{Malware Fullpath}", {Export} {First Argument} {Second Argument} {Third Argument}

Other Details

This Trojan does the following:

  • It checks if it is executed with the following arguments:
  • If it is executed without argument:
    • It adds one of the following process randomly:
      • cmd /c timeout /t 6 & "%System%\rundll32.exe" "{Malware Fullpath}", {Export} {First Argument} {Second Argument} & exit
      • cmd /c choice /n /c y /d y /t 6 & "%System%\rundll32.exe" "{Malware Fullpath}", {Export} {First Argument} {Second Argument} & exit
      • cmd /c timeout 10 /nobreak & "%System%\rundll32.exe" "{Malware Fullpath}", {Export} {First Argument} {Second Argument} & exit
      • cmd /c ping 192.0.2.210 -n 8 -i 103 -4 -w 1000 > NUL & "%System%\rundll32.exe" "{Malware Fullpath}", {Export} {First Argument} {Second Argument} & exit
  • If it is executed with two specified arguments:
    • It adds the following process:
      • cmd.exe /c reg.exe add HKCU\Software\Microsoft\Windows\CurrentVersion\Run /f /v 0q0ci6sB1gW5cD8sS6T /t REG_SZ /d "\"%System%\rundll32.exe\" \"{Malware Fullpath}\", {Export} {First Argument} {Second Argument} {Third Argument}"
    • It adds one of the following process randomly:
      • cmd /c timeout /t 6 & "%System%\rundll32.exe" "{Malware Fullpath}", {Export} {First Argument} {Second Argument} {Third Argument} & exit
      • cmd /c choice /n /c y /d y /t 6 & "%System%\rundll32.exe" "{Malware Fullpath}", {Export} {First Argument} {Second Argument} {Third Argument} & exit
      • cmd /c timeout 10 /nobreak & "%System%\rundll32.exe" "{Malware Fullpath}", {Export} {First Argument} {Second Argument} {Third Argument} & exit
      • cmd /c ping 192.0.2.210 -n 8 -i 103 -4 -w 1000 > NUL & "%System%\rundll32.exe" "{Malware Fullpath}", {Export} {First Argument} {Second Argument} {Third Argument} & exit
  • If it is executed with three specified arguments:
    • It adds the following process:
      • cmd.exe /c reg.exe query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths"
      • cmd.exe /c reg.exe query "HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\chrome.exe" /v "Path"
      • "%Program Files%\Google\Chrome\Application\chrome.exe" {First Argument} {Second Argument} {Third Argument} {Fourth Argument} "{Malware Fullpath}" "rundll32.exe" {Export}
  • It injects malicious code to the added process, chrome.exe. --> will only work if executed on Windows 10

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.. %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000(32-bit), Server 2003(32-bit), XP, Vista(64-bit), 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit) , or C:\Program Files (x86) in Windows XP(64-bit), Vista(64-bit), 7(64-bit), 8(64-bit), 8.1(64-bit), 2008(64-bit), 2012(64-bit) and 10(64-bit).)

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 17.272.06
FIRST VSAPI PATTERN DATE: 24 Dec 2021
VSAPI OPR PATTERN File: 17.273.00
VSAPI OPR PATTERN Date: 25 Dec 2021

Step 1

Trend Micro Predictive Machine Learning detects and blocks malware at the first sign of its existence, before it executes on your system. When enabled, your Trend Micro product detects this malware under the following machine learning name:

     
    • TSPY.Win32.TRX.XXPE50FFF051E0002

Step 2

Before doing any scans, Windows 7, Windows 8, Windows 8.1, and Windows 10 users must disable System Restore to allow full scanning of their computers.

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry value

[ Learn More ]

Important: Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this step only if you know how or you can ask assistance from your system administrator. Else, check this Microsoft article first before modifying your computer's registry.

  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • {Random Characters} = "%System%\rundll32.exe\" "{Malware Fullpath}", {Export} {First Argument} {Second Argument} {Third Argument}

Step 5

Restart in normal mode and scan your computer with your Trend Micro product for files detected as Trojan.Win64.BAZARLOADER.FAJG. If the detected files have already been cleaned, deleted, or quarantined by your Trend Micro product, no further step is required. You may opt to simply delete the quarantined files. Please check this Knowledge Base page for more information.


Did this description help? Tell us how we did.