Analysis by: Christopher Daniel So
ALIASES:

TrojanDownloader:Win32/Abgade.A (Microsoft), SpywareGuard2008 (Symantec), Trojan-Ransom.Win32.XBlocker.aok (Kaspersky)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Trojan

  • Destructiveness: Yes

  • Encrypted: Yes

  • 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: Varies
File Type: PE
Memory Resident: No
Initial Samples Received Date: 09 Jun 2010

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:

  • %User Temp%\3HP4568tQ1aJl1S.exe

(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.)

It drops the following files:

  • %Desktop%\COMO DESENCRIPTAR ARCHIVOS!!!.txt

(Note: %Desktop% is the current user's desktop, which is usually C:\Windows\Profiles\{user name}\Desktop on Windows 98 and ME, C:\WINNT\Profiles\{user name}\Desktop on Windows NT, and C:\Documents and Settings\{User Name}\Desktop on Windows 2000, XP, and Server 2003.)

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CLASSES_ROOT\.ENCRYPTED!!!

HKEY_CLASSES_ROOT\PMVPITBREEAODSF

It adds the following registry entries:

HKEY_CLASSES_ROOT\.ENCRYPTED!!!
(Default) = "PMVPITBREEAODSF"

HKEY_CLASSES_ROOT\PMVPITBREEAODSF
(Default) = "CRYPTED!"

HKEY_CLASSES_ROOT\PMVPITBREEAODSF\DefaultIcon
(Default) = "%User Temp%\3HP4568tQ1aJl1S.exe,0"

HKEY_CLASSES_ROOT\PMVPITBREEAODSF\shell\
open\command
(Default) = "%User Temp%\3HP4568tQ1aJl1S.exe"

Other Details

This Trojan encrypts files with the following extensions:

  • bmp
  • doc
  • gif
  • htm
  • html
  • jpg
  • lnk
  • mdb
  • pdf
  • png
  • ppt
  • txt
  • xls
  • zip

  SOLUTION

Minimum Scan Engine: 8.900
VSAPI PATTERN File: 7.792.15
VSAPI PATTERN Date: 26 Jan 2011
VSAPI PATTERN Date: 1/26/2011 12:00:00 AM

Step 1

For Windows XP and Windows Server 2003 users, before doing any scans, please make sure you disable System Restore to allow full scanning of your computer.

Step 2

Identify and terminate files detected as TROJ_RANSOM.JL

[ Learn More ]
  1. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  2. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

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_CLASSES_ROOT
    • .ENCRYPTED!!!
  • In HKEY_CLASSES_ROOT
    • PMVPITBREEAODSF

Step 4

Search and delete this file

[ 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. %Desktop%\COMO DESENCRIPTAR ARCHIVOS!!!.txt

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_RANSOM.JL. 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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