Analysis by: kathleenno
ALIASES:

Backdoor:Win32/Bifrose (Microsoft); Trojan-Spy.Win32.Small.csj (Kaspersky)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • Threat Type: Backdoor

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

This backdoor arrives as a file that exports the functions of other malware/grayware. It 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: 95,798 bytes
File Type: DLL
Memory Resident: Yes
Initial Samples Received Date: 26 May 2011

Arrival Details

This backdoor arrives as a file that exports the functions of other malware/grayware.

It 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 backdoor adds the following registry entries:

HKEY_CURRENT_USER\Software\Google
ActiveSettings = "{hex value}"

Other Details

This backdoor connects to the following possibly malicious URL:

  • {BLOCKED}v.{BLOCKED}s.us

  SOLUTION

Minimum Scan Engine: 8.900
FIRST VSAPI PATTERN FILE: 8.182.15
FIRST VSAPI PATTERN DATE: 26 May 2011

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

Restart in normal mode and scan your computer with your Trend Micro product for files detected as BKDR_BIFROSE.DPQ. 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 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\Google
    • ActiveSettings = {hex value}

Step 4

Scan your computer with your Trend Micro product to delete files detected as BKDR_BIFROSE.DPQ. 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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