Analysis by: Byron Jon Gelera

ALIASES:

ALS.Jiwai (Symantec); Virus.Acad.Bursted.b (Kaspersky); Virus:ALisp/Bursted.BL (Microsoft)

 PLATFORM:

Windows

 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.

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

  TECHNICAL DETAILS

File Size: 6,697 bytes
File Type: LSP
Memory Resident: No
Initial Samples Received Date: 18 Oct 2011

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.

Other System Modifications

This Trojan modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
SHOWALL
CheckedValue = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
NOHIDDEN
CheckedValue = 0

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
Advanced\Folder\Hidden\
NOHIDDEN
DefaultValue = 0

Other Details

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

  SOLUTION

Minimum Scan Engine: 9.800
FIRST VSAPI PATTERN FILE: 8.508.02
FIRST VSAPI PATTERN DATE: 19 Oct 2011
VSAPI OPR PATTERN File: 8.509.00
VSAPI OPR PATTERN Date: 20 Oct 2011

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

Restore this modified 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\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\SHOWALL
    • CheckedValue = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\NOHIDDEN
    • CheckedValue = 0
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Advanced\Folder\Hidden\NOHIDDEN
    • DefaultValue = 0

Step 3

Scan your computer with your Trend Micro product to delete files detected as ALS_BURSTED.CNI. 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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