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TROJ_OLMASCO.AJ

February 19, 2013
 Analysis by: Rika Joi Gregorio
 ALIASES:

Trojan:Win32/Alureon.EN(Microsoft), Trojan.Win32.Alureon(Ikarus), Win32/Olmasco.O trojan(Eset)

 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:

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


This Trojan may arrive bundled with malware packages as a malware component.

It requires its main component to successfully perform its intended routine.

  TECHNICAL DETAILS

File Size:

26,624 bytes

File Type:

DLL

Memory Resident:

Yes

Initial Samples Received Date:

14 Feb 2013

Arrival Details

This Trojan may arrive bundled with malware packages as a malware component.

Other System Modifications

This Trojan deletes the following files:

  • %System%\drivers\mbam.sys

(Note: %System% is the Windows system folder, which is usually C:\Windows\System32.)

It deletes the following registry keys:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\IpFilterDriver

Other Details

This Trojan requires its main component to successfully perform its intended routine.

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.726.07

FIRST VSAPI PATTERN DATE:

14 Feb 2013

VSAPI OPR PATTERN File:

9.727.00

VSAPI OPR PATTERN Date:

15 Feb 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

Scan your computer with your Trend Micro product and note files detected as TROJ_OLMASCO.AJ

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete the files detected as TROJ_OLMASCO.AJ

*Note: Some component files may be 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.

To stop the malware/grayware from running when certain files are opened:

For Windows 2000, Windows XP, and Windows Server 2003:

  1. Right-click Start then click Search....
  2. In the Named input box, type the name of the file that was detected earlier.
  3. In the Look In drop-down list, select My Computer then press Enter.
  4. Once located, select the file then press SHIFT+DELETE to delete it.

For Windows Vista and Windows 7:

  1. Click Start>Computer.
  2. In the Search Computer input box, type the name of the file detected earlier, and press Enter.
  3. Once located, select the file then press SHIFT+DELETE to delete it.
    *Note: Read the following Microsoft page if these steps do not work on Windows 7.

Step 5

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

Step 6

Restore this deleted registry key/value from backup

*Note: Only Microsoft-related keys/values will be restored. If the malware/grayware also deleted registry keys/values related to programs that are not from Microsoft, please reinstall those programs on your computer.

  • HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\IpFilterDriver

Step 7

Restore this file from backup only Microsoft-related files will be restored. If this malware/grayware also deleted files related to programs that are not from Microsoft, please reinstall those programs on you computer again.  

  • %System%\drivers\mbam.sys


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