WORM_DLOAD.AQWA


 ALIASES:

Panda : W32/Ircbot.DAL.worm; Kaspersky : Trojan.Win32.Menti.bbm

 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: Yes

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Propagates via removable drives

This worm drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

It executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  TECHNICAL DETAILS

File Size:

43,615 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

05 Mar 2011

Payload:

Downloads files

Installation

This worm drops the following copies of itself into the affected system:

  • %System Root%\RECYCLER\(SID}\acleaner.exe

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It drops the following non-malicious files:

  • [REMOVABLE DRIVE]:\RECYCLER\(SID}\Desktop.ini
  • %System Root%\RECYCLER\(SID}\Desktop.ini

(Note: %System Root% is the root folder, which is usually C:\. It is also where the operating system is located.)

It injects itself into the following processes as part of its memory residency routine:

  • explorer.exe

Autostart Technique

This worm adds the following registry entries to enable its automatic execution at every system startup:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows NT\CurrentVersion\Winlogon
Taskman = %System Root%\RECYCLER\(SID}\acleaner.exe

Propagation

This worm drops the following copy(ies) of itself in all removable drives:

  • [DRIVE]:\RECYCLER\(SID}\acleaner.exe

It drops an AUTORUN.INF file to automatically execute the copies it drops when a user accesses the drives of an affected system.

The said .INF file contains the following strings:

{garbage codes}
[autorun]
open=RECYCLER\R-1-5-21-1482476501-1644491937-682003330-1013\acleaner.exe
{garbage codes}
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
shell\open=Open
shell\open\command=RECYCLER\R-1-5-21-1482476501-1644491937-682003330-1013\acleaner.exe
{garbage codes}
shell\open\default=1
{garbage codes}

Download Routine

This worm accesses the following websites to download files:

  • http://{BLOCKED}o.natnatraoi.com/ms.exe

Trend Micro detects the dowloaded file as:

  • WORM_KOLAB.SML

It then executes the downloaded files. As a result, malicious routines of the downloaded files are exhibited on the affected system.

  SOLUTION

Minimum Scan Engine:

8.900

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 WORM_DLOAD.AQWA

    WORM_KOLAB.SML

Step 3

Identify and delete files detected as WORM_DLOAD.AQWA using the Recovery Console

[ Learn More ]

Step 4

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_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Winlogon
    • Taskman = %System Root%\RECYCLER\(SID}\acleaner.exe

Step 5

Search and delete these folders

[ 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.
[REMOVABLE DRIVE]:\RECYCLER\(SID}
%System Root%\RECYCLER\(SID}

Step 6

Search and delete AUTORUN.INF files created by WORM_DLOAD.AQWA that contain these strings

[ Learn More ]
{garbage codes}
[autorun]
open=RECYCLER\R-1-5-21-1482476501-1644491937-682003330-1013\acleaner.exe
{garbage codes}
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
shell\open=Open
shell\open\command=RECYCLER\R-1-5-21-1482476501-1644491937-682003330-1013\acleaner.exe
{garbage codes}
shell\open\default=1
{garbage codes}

Step 7

Scan your computer with your Trend Micro product to delete files detected as WORM_DLOAD.AQWA. 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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