WORM_SOCKS.DCD

 Analysis by: Anthony Joe Melgarejo

 ALIASES:

TrojanDropper:Win32/Emold.C (Microsoft), W32.SillyFDC (Symantec), W32/Autorun.worm.aah (McAfee), Mal/FakeAV-BT (Sophos), W32/Worm.APBE (F-Prot), W32/AutoRun.FJD!worm (Fortinet), W32/AutoRun.DJ.worm (Panda), BScope.Worm.Win32.AutoRun.oik (VBA32)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit)

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted:

  • In the wild: Yes

  OVERVIEW


This worm arrives via removable drives.

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

  TECHNICAL DETAILS

File Size:

32,256 bytes

File Type:

EXE

Memory Resident:

Yes

Initial Samples Received Date:

28 Jan 2013

Arrival Details

This worm arrives via removable drives.

Installation

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

  • %Program Files%\Microsoft Common\svchost.exe

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files in Windows 2000, Server 2003, and XP (32-bit), Vista (32-bit), and 7 (32-bit), or C:\Program Files (x86) in Windows XP (64-bit), Vista (64-bit), and 7 (64-bit).)

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\Image File Execution Options\
explorer.exe
Debugger = "%Program Files%\Microsoft Common\svchost.exe"

Propagation

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

  • {drive letter}:\autorun.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:

[autorun]
;{random letter}
open=autorun.exe
;{random letter}
shellexecute=autorun.exe
;{random letter}
shell\Explore\command=autorun.exe
;{random letter}
shell\Open\command=autorun.exe
;{random letter}
shell=Explore

Other Details

This worm connects to the following possibly malicious URL:

  • http://{BLOCKED}o-kuba.net

  SOLUTION

Minimum Scan Engine:

9.300

FIRST VSAPI PATTERN FILE:

9.700.01

FIRST VSAPI PATTERN DATE:

01 Feb 2013

VSAPI OPR PATTERN File:

9.701.00

VSAPI OPR PATTERN Date:

02 Feb 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

Restart in Safe Mode

[ Learn More ]

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.

  • HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Image File Execution Options\explorer.exe
  • Debugger = "%Program Files%\Microsoft Common\svchost.exe"

Step 4

Search and delete AUTORUN.INF files created by WORM_SOCKS.DCD that contain these strings

[ Learn More ]
[autorun]
;{random letter}
open=autorun.exe
;{random letter}
shellexecute=autorun.exe
;{random letter}
shell\Explore\command=autorun.exe
;{random letter}
shell\Open\command=autorun.exe
;{random letter}
shell=Explore

Step 5

Search and delete these files

[ Learn More ]
There may be some 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.
  • {drive letter}:\autorun.exe

Step 6

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