TROJ_AGENT.BFNQ

 Analysis by: Jimelle Monteser

 ALIASES:

Trojan.Win32.Agent.yzor (Kaspersky)

 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: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Downloaded from the Internet, Dropped by other malware


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 does not have any propagation routine.

It does not have any backdoor routine.

As of this writing, the said sites are inaccessible.

It does not have any information-stealing capability.

It deletes the initially executed copy of itself.

  TECHNICAL DETAILS

File Size:

183,296 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

13 Jun 2013

Payload:

Connects to URLs/IPs

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:

  • %Application Data%\AudioCard\vAudioCard.exe

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

It creates the following folders:

  • %Application Data%\AudioCard

(Note: %Application Data% is the current user's Application Data folder, which is usually C:\Documents and Settings\{user name}\Application Data on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Roaming on Windows Vista and 7.)

Propagation

This Trojan does not have any propagation routine.

Backdoor Routine

This Trojan does not have any backdoor routine.

Download Routine

This Trojan connects to the following website(s) to download and execute a malicious file:

  • http://{BLOCKED}nzo.pw/1370452770_0.71825600.exe

As of this writing, the said sites are inaccessible.

Information Theft

This Trojan does not have any information-stealing capability.

Other Details

This Trojan deletes the initially executed copy of itself

NOTES:

This Trojan does not have rootkit capabilities and does not exploit any vulnerability.

It adds the following registry key and entries if the affected system is running on Windows 7:

HKEY_LOCAL_MACHINE\Software\Microsoft\{malware file name}_RASAPI32

HKEY_LOCAL_MACHINE\Software\Microsoft\{malware file name}_RASMANCS

HKEY_LOCAL_MACHINE\Software\Microsoft\{malware file name}_RASAPI32
EnableFileTracing = "0"
EnableConsoleTracing = "0"
FileTracingMask = "4294901760"
ConsoleTracingMask = "4294901760"
MaxFileSize = "1048576"
FileDirectory = "%Windows%\tracing"

HKEY_LOCAL_MACHINE\Software\Microsoft\{malware file name}_RASMANCS
EnableFileTracing = "0"
EnableConsoleTracing = "0"
FileTracingMask = "4294901760"
ConsoleTracingMask = "4294901760"
MaxFileSize = "1048576"
FileDirectory = "%Windows%\tracing"

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.988.02

FIRST VSAPI PATTERN DATE:

18 Jun 2013

VSAPI OPR PATTERN File:

9.989.00

VSAPI OPR PATTERN Date:

19 Jun 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_AGENT.BFNQ

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_LOCAL_MACHINE\Software\Microsoft
    • {malware file name}_RASAPI32
  • In HKEY_LOCAL_MACHINE\Software\Microsoft
    • {malware file name}_RASMANCS

Step 4

Search and delete this folder

[ Learn More ]
Please make sure you check the Search Hidden Files and Folders checkbox in the More advanced options option to include all hidden folders in the search result.  
  • %Application Data%\AudioCard

Step 5

Scan your computer with your Trend Micro product to delete files detected as
 TROJ_AGENT.BFNQ


*Note: 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.

NOTES:

Note: Users who are not on Windows 7 shoud skip step 3 and proceed to step 4.


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