Analysis by: Cris Nowell Pantanilla
 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW

Infection Channel: Downloaded from the Internet, Dropped by other malware

This malware uses social engineering to lure users into performing actions that may end up compromising themselves. Specifically, it purports to be involved with the Federal Bureau of Investigation or any police authority. It uses an audio recording, in the form of an .MP3 file, that repeatedly informs users that their system is blocked because of a certain violation on the federal law that the malware alleges the user committed.

To get a one-glance comprehensive view of the behavior of this Trojan, refer to the Threat Diagram shown below.

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 connects to certain websites to send and receive information.

  TECHNICAL DETAILS

File Size: 371,200 bytes
File Type: EXE
Memory Resident: Yes
Initial Samples Received Date: 02 Oct 2012
Payload: Locks systems

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 adds the following registry entries to enable its automatic execution at every system startup:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Microsoft Updater = "{malware path and filename}"

Process Termination

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

  • taskmgr.exe
  • msconfig.exe
  • regedit.exe
  • cmd.exe

Other Details

This Trojan connects to the following website to send and receive information:

  • {BLOCKED}.{BLOCKED}.156.30
  • {BLOCKED}.{BLOCKED}.229.104
  • {BLOCKED}.{BLOCKED}.44.239
  • {BLOCKED}.{BLOCKED}.165.210

NOTES:

Once the malware is executed, It will lock the user's system and displays the following screen where a fake FBI message is displayed:

It will also drop a normal audio file, 1.mp3, in the malware's current directory where the message 'FBI warning! Your computer is blocked for violation of federal law.' is played.

To unlock the system, the user is forced to pay $200 (USD) via MoneyPak.

  SOLUTION

Minimum Scan Engine: 9.200
FIRST VSAPI PATTERN FILE: 9.448.04
FIRST VSAPI PATTERN DATE: 04 Oct 2012
VSAPI OPR PATTERN File: 9.449.00
VSAPI OPR PATTERN Date: 09 Oct 2012

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

Scan your computer with your Trend Micro product and note files detected as TROJ_RANSOM.CXB

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
    • Microsoft Updater = "{malware path and filename}"

Step 5

Search and delete the file detected as TROJ_RANSOM.CXB

[ Learn More ]

Step 6

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