Trojan.Win32.CERBER.AA

June 02, 2020
 PLATFORM:

Windows

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

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:

1,086,062 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

02 Jun 2020

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.

Other System Modifications

This Trojan adds the following registry entries:

hkey_current_user\software\microsoft\
directinput\{malware file name}.dat538a75fa0010926e
Name = "{malware file name}.dat"

hkey_current_user\software\microsoft\
directinput\{malware file name}.dat538a75fa0010926e
UsesMapper = "\x00\x00\x00\x00"

HKEY_CURRENT_USER\Software\Microsoft\
DirectInput\MostRecentApplication
Name = "{malware file name}.dat"

HKEY_CURRENT_USER\Software\Microsoft\
DirectInput\MostRecentApplication
Id = "{malware file name}.dat538a75fa0010926e"

HKEY_CURRENT_USER\Software\Microsoft\
DirectInput\MostRecentApplication
Version = "\x00\x08\x00\x00"

HKEY_CURRENT_USER\Software\Microsoft\
DirectInput\MostRecentApplication
MostRecentStart = "j\xb7+\xef\xd9\xd5\x01"

HKEY_CURRENT_USER\Software\Microsoft\
Speech\PhoneConverters
DefaultTokenId = "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Speech\PhoneConverters\Tokens\English"

Dropping Routine

This Trojan drops the following files:

  • %User Temp%\log.txt

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000(32-bit), XP, and Server 2003(32-bit), or C:\Users\{user name}\AppData\Local\Temp on Windows Vista, 7, 8, 8.1, 2008(64-bit), 2012(64-bit) and 10(64-bit).)

Other Details

This Trojan connects to the following possibly malicious URL:

  • http://home.{BLOCKED}lon.com

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.850

Step 1

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 2

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\directinput\{malware file name}.dat538a75fa0010926e
    • Name = "{malware file name}.dat"
  • In hkey_current_user\software\microsoft\directinput\{malware file name}.dat538a75fa0010926e
    • UsesMapper = "\x00\x00\x00\x00"
  • In HKEY_CURRENT_USER\Software\Microsoft\DirectInput\MostRecentApplication
    • Name = "{malware file name}.dat"
  • In HKEY_CURRENT_USER\Software\Microsoft\DirectInput\MostRecentApplication
    • Id = "{malware file name}.dat538a75fa0010926e"
  • In HKEY_CURRENT_USER\Software\Microsoft\DirectInput\MostRecentApplication
    • Version = "\x00\x08\x00\x00"
  • In HKEY_CURRENT_USER\Software\Microsoft\DirectInput\MostRecentApplication
    • MostRecentStart = "j\xb7+\xef\xd9\xd5\x01"
  • In HKEY_CURRENT_USER\Software\Microsoft\Speech\PhoneConverters
    • DefaultTokenId = "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Speech\PhoneConverters\Tokens\English"

Step 3

Search and delete this file

[ Learn More ]
There may be some files that are hidden. Please make sure you check the Search Hidden Files and Folders checkbox in the "More advanced options" option to include all hidden files and folders in the search result.
  • %User Temp%\log.txt

Step 4

Scan your computer with your Trend Micro product to delete files detected as Trojan.Win32.CERBER.AA. 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 the following Trend Micro Support pages for more information:


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