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TROJ_RANSOM.JLM

January 07, 2014
 Analysis by: Mark Joseph Manahan
 ALIASES:

Trojan:Win32/PossibleMalware.A (Microsoft), a variant of Win32/Spy.Aibatook.E trojan (Eset), RDN/Ransom!dx (McAfee)

 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


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:

178,688 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

03 Jan 2014

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 adds the following possibly malicious files or file components:

  • %Application Data%\{random}.dll
  • %Application Data%\ini.ini

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

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
TcpIPCfg = Rundll32 "%Application Data%\{random}.dll",MainThread

Other System Modifications

This Trojan adds the following registry entries as part of its installation routine:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Internet Settings
ProxyOverride = ""

Other Details

This Trojan connects to the following possibly malicious URL:

  • www.{BLOCKED}d.com/lib.txt?{random}
  • www.{BLOCKED}d.com/html.txt?{random}

  SOLUTION

Minimum Scan Engine:

9.700

FIRST VSAPI PATTERN FILE:

10.498.04

FIRST VSAPI PATTERN DATE:

26 Dec 2013

VSAPI OPR PATTERN File:

10.499.00

VSAPI OPR PATTERN Date:

26 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

Restart in Safe Mode

[ Learn More ]

Step 3

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
    • TcpIPCfg = Rundll32 "%Application Data%\{random}.dll",MainThread
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Internet Settings
    • ProxyOverride = "<local>"

Step 4

Search and delete these files

[ Learn More ]
There may be some component 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.
  • %Application Data%\{random}.dll - refer to autorun registry
  • %Application Data%\ini.ini

Step 5

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