TROJ_DLOAD.QYUA

 Analysis by: Kathleen Notario

 PLATFORM:

Windows 2000, Windows XP, Windows Server 200

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

  • Threat Type: Trojan

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW


This Trojan executes the file ipconfig.exe. If unsuccessful, it will terminate itself. It has a routine that adds garbage data to the resource section of its dropped files, making their sizes vary.

This Trojan may be downloaded by other malware/grayware from remote sites.

It opens a hidden Internet Explorer window. It deletes itself after execution.

  TECHNICAL DETAILS

File Size:

73,728 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

26 Jan 2012

Payload:

Connects to URLs/IPs, Drops files

Arrival Details

This Trojan may be downloaded by the following malware/grayware from remote sites:

  • HTML_EXPLT.QYUA

Installation

This Trojan drops and executes the following files:

  • %System%\drivers\com32.sys - detected as RTKT_MDIEXP.QYUA
  • %System%\com32.dll - also detected as TROJ_DLOAD.QYUA

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It drops the following non-malicious file:

  • %System%\VersionKey.ini

(Note: %System% is the Windows system folder, which is usually C:\Windows\System on Windows 98 and ME, C:\WINNT\System32 on Windows NT and 2000, or C:\Windows\System32 on Windows XP and Server 2003.)

It adds the following mutexes to ensure that only one of its copies runs at any one time:

  • RktDownload{random numbers}

Other Details

This Trojan opens a hidden Internet Explorer window.

It deletes itself after execution.

NOTES:

It executes the file ipconfig.exe. If unsuccessful, it will terminate itself.

It has a routine that adds garbage data to the resource section of its dropped files, making their sizes vary.

It checks if any of the following processes are running:

  • SpStart.exe
  • IRPro.exe
  • Remon.exe

If found, it drops and executes the file %System%\FileDisk.sys also detected as RTKT_MDIEXP.QYUA. It then copies itself as Z:\WINDOWS\system32\userinit.exe.

The DLL component file accesses the following URL to download its configuration file:

  • http://file.{BLOCKED}egirl.com/20120120.jpg

It saves the downloaded file as %User Temp%\fuc{number}.tmp. The said configuration file contains the following URL that it accesses to download and execute a malicious file:

  • http://file.{BLOCKED}egirl.com/20120120.exe - detected as TSPY_ONLING.KREA

It checks if any of the following processes related to antivirus are running:

  • AYRTSrv.aye
  • ALYac.aye
  • AYServiceNT.aye
  • v3light.exe
  • v3lsvc.exe
  • v3ltray.exe
  • NVCAgent.npc
  • nsvmon.npc
  • Nsavsvc.npc

If found it will modify the privileges of the said process. It will then delete its configuration file.

  SOLUTION

Minimum Scan Engine:

9.200

FIRST VSAPI PATTERN FILE:

8.732.07

FIRST VSAPI PATTERN DATE:

26 Jan 2012

VSAPI OPR PATTERN File:

8.733.00

VSAPI OPR PATTERN Date:

26 Jan 2012

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

Remove malware files dropped/downloaded by TROJ_DLOAD.QYUA

Step 3

Restart in Safe Mode

[ Learn More ]

Step 4

Search and delete this file

[ Learn More ]
There may be some component files that are 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.  
  • %System%\VersionKey.ini

Step 5

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