Analysis by: Jimelle Monteser
ALIASES:

TrojanDropper:Win32/Zegost.B (Microsoft), W32/Bjlog.LBY!tr.pws (Fortinet), Trojan-Dropper.SuspectCRC (Ikarus), Trojan-PSW.Win32.Bjlog.dtwr (Kaspersky)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • 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.

It does not have any propagation routine.

It does not have any backdoor routine.

It does not have any downloading capability.

It does not have any information-stealing capability.

It deletes itself after execution.

  TECHNICAL DETAILS

File Size: 20,957,737 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 19 Dec 2013

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 copies of itself into the affected system:

  • %System Root%\{random}

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It creates the following folders:

  • %All Users Profile%\DRM\%SESSIONNAME%

Autostart Technique

This Trojan registers itself as a system service to ensure its automatic execution at every system startup by adding the following registry entries:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ
FailureActions = "{hex values}"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ\Parameters
seRVicemAIN = "NPGetResourceParent"

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\HidServ\Parameters
module = "%System Root%\{random}"

Other System Modifications

This Trojan adds the following registry keys:

HKEY_LOCAL_MACHINE\Software\{random}

HKEY_LOCAL_MACHINE\Software\{random}\
Parameters

It adds the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\{random}
DependsOnService = "RpcSs"

HKEY_LOCAL_MACHINE\SOFTWARE\{random}
ErrorControl = "1"

HKEY_LOCAL_MACHINE\SOFTWARE\{random}
ObjectName = "LocalSystem"

HKEY_LOCAL_MACHINE\SOFTWARE\{random}
Start = "4"

HKEY_LOCAL_MACHINE\SOFTWARE\{random}
Type = "32"

HKEY_LOCAL_MACHINE\SOFTWARE\{random}
seRVicemAIN = "NPGetResourceParent"

HKEY_LOCAL_MACHINE\SOFTWARE\{random}
seRVicedlL = "%All Users Profile%\DRM\%SESSIONNAME%\{random}.cc3"

HKEY_LOCAL_MACHINE\SOFTWARE\{random}
module = "%System Root%\{random}"

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Dropping Routine

This Trojan drops the following files:

  • %All Users Profile%\DRM\%SESSIONNAME%\{random}.cc3 - detected as BKDR_REDOSD.SMX
  • %User Temp%\{random}.dat - detected as BKDR_REDOSD.SMX
  • %System%\{random}.rdb

(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, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.. %System% is the Windows system folder, which is usually C:\Windows\System32.)

Download Routine

This Trojan does not have any downloading capability.

Information Theft

This Trojan does not have any information-stealing capability.

Other Details

This Trojan deletes itself after execution.

NOTES:

This Trojan accepts the following parameters:

  • -s (register itself as service)

It does not have rootkit capabilities.

It does not exploit any vulnerability.

  SOLUTION

Minimum Scan Engine: 9.700
VSAPI OPR PATTERN File: 10.473.00
VSAPI OPR PATTERN Date: 15 Dec 2013

Step 1

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

Step 2

Remove malware/grayware files dropped/downloaded by TROJ_BJLOG.VG

    • BKDR_REDOSD.SMX

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Delete this registry key

[ 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_LOCAL_MACHINE\Software
    • {random}

Step 5

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_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ
    • FailureActions = "{hex values}"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ\Parameters
    • seRVicemAIN = "NPGetResourceParent"
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\HidServ\Parameters
    • module = "%System Root%\{random}"

Step 6

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.
  • %All Users Profile%\DRM\%SESSIONNAME%

Step 7

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.
  • %System%\{random}.rdb

Step 8

Restart in normal mode and scan your computer with your Trend Micro product for files detected as TROJ_BJLOG.VG. 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.


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