TROJ_VUNDO.DBA


 ALIASES:

Trojan:Win32/Vundo.gen!L (Microsoft); DNSChanger.p (McAfee); Trojan.Zlob (Symantec); Trojan.Win32.Monder.gen (Kaspersky); Trojan.Win32.Vundo.l (v) (Sunbelt); Trojan horse DNSChanger.AB (AVG)

 PLATFORM:

Windows 2000, Windows XP, Windows Server 2003

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

  • 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 deletes itself after execution.

  TECHNICAL DETAILS

File Size:

57,856 bytes

File Type:

EXE

Memory Resident:

No

Initial Samples Received Date:

30 May 2013

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:

  • %System%\dmpqa.exe

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

Other System Modifications

This Trojan adds the following registry keys:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\_r

It adds the following registry entries:

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion
dmpqa.exe = "{random values}"

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\_r
aqpmd = "{random values}"

It modifies the following registry entries:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Explorer\
BrowseNewProcess
BrowseNewProcess = "yes"

(Note: The default value data of the said registry entry is yes.)

Other Details

This Trojan deletes itself after execution.

This report is generated via an automated analysis system.

  SOLUTION

Minimum Scan Engine:

9.300

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

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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion
    • _r

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\Microsoft\Windows\CurrentVersion
    • dmpqa.exe = "{random values}"
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\_r
    • aqpmd = "{random values}"

Step 4

Restore these modified registry values

[ Learn More ]

Important:Editing the Windows Registry incorrectly can lead to irreversible system malfunction. Please do this only if you know how to or you can seek your system administrator's help. You may also check out this Microsoft article first before modifying your computer's registry.

  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\BrowseNewProcess
    • From: BrowseNewProcess = "yes"
      To: BrowseNewProcess = ""yes""

Step 5

Scan your computer with your Trend Micro product to delete files detected as TROJ_VUNDO.DBA. 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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