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WORM_PROLAC.AA

October 08, 2012
 Analysis by: Sabrina Lei Sioting
 PLATFORM:

Windows 2000, XP, Server 2003

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

  • Threat Type: Worm

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel:

Propagates via removable drives, Propagates via peer-to-peer networks

The dropped AUTORUN.INF is detected by Trend Micro as Mal_Otorun1.

This worm arrives as attachment to mass-mailed email messages. It 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.

It also has rootkit capabilities, which enables it to hide its processes and files from the user.

  TECHNICAL DETAILS

File Size:

475,648 bytes

File Type:

EXE

Memory Resident:

No

Payload:

Hides files and processes

Arrival Details

This worm arrives as attachment to mass-mailed email messages.

It arrives via removable drives.

It may arrive via network shares.

Installation

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

  • %system%\AdobeAOM.exe

It drops and executes the following files:

  • %Windows%\cuesvc.dll - detected by Trend Micro as TROJ_HILOTI.SMAE
  • %System%\adobeavi.exe - detected by Trend Micro as TROJ_HILOTI.SMAE
  • %System%\adobemp4.exe - detected by Trend Micro as TROJ_FAKEAV.SM2

(Note: %Windows% is the Windows folder, which is usually C:\Windows or C:\WINNT.. %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.)

Autostart Technique

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

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Run
Adobe Updater 8.2 = %system%\AdobeAOM.exe

Other System Modifications

This worm adds the following registry keys:

HKEY_LOCAL_MACHINE\SOFTWARE\AdobeARM8

HKEY_CURRENT_USER\Software\AdobeARM8

It adds the following registry entries as part of its installation routine:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\
Services\SharedAccess\Parameters\
FirewallPolicy\StandardProfile\AuthorizedApplications\
List
%system%\AdobeAOM.exe = %system%\AdobeAOM.exe:*:Enabled:Explorer

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer
gnome8ass = {month of execution}

HKEY_CURRENT_USER\Software\Microsoft\
Windows\CurrentVersion\Explorer
gnome8ass = {day of execution}

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Security Center
UACDisableNotify = 1

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\policies\
system
EnableLUA = 1

Propagation

This worm creates the following folders in all removable drives:

  • RECYCLER\S-1-6-21-2434476521-1645645927-702000330-1542
  • RECYCLER

It drops copies of itself into the following folders used in peer-to-peer (P2P) networks:

  • %Program Files%\emule\incoming

(Note: %Program Files% is the default Program Files folder, usually C:\Program Files.)

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

  • RECYCLER\S-1-6-21-2434476521-1645645927-702000330-1542\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]
open=RECYCLER\S-1-6-21-2434476521-1645645927-702000330-1542\autorun.exe
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
shell\open=Open
shell\open\command=RECYCLER\S-1-6-21-2434476521-1645645927-702000330-1542\autorun.exe
shell\open\default=1

Rootkit Capabilities

This worm also has rootkit capabilities, which enables it to hide its processes and files from the user.

Other Details

This worm did not exhibit backdoor routines during testing.

It does the following:

  • It uses the following file names for its dropped copies in P2P shares:
    • Ad-aware 2010.exe
    • AVS Video Converter v6.3.1.365 CRACKED.exe
    • Adobe Acrobat Reader keygen.exe
    • Adobe Illustrator CS4 crack.exe
    • Adobe Photoshop CS5 crack.exe
    • Alcohol 120 v1.9.7.exe
    • Anti-Porn v13.5.12.29.exe
    • AnyDVD HD v.6.3.1.8 Beta incl crack.exe
    • Ashampoo Snap 3.02.exe
    • BitDefender AntiVirus 2010 Keygen.exe
    • Blaze DVD Player Pro v6.52.exe
    • CleanMyPC Registry Cleaner v6.02.exe
    • DVD Tools Nero 10.5.6.0.exe
    • Daemon Tools Pro 4.50.exe
    • Divx Pro 7 + keymaker.exe
    • Download Accelerator Plus v9.exe
    • Download Boost 2.0.exe
    • G-Force Platinum v3.7.5.exe
    • Google SketchUp 7.1 Pro.exe
    • Grand Theft Auto Episodes From Liberty City 2010.exe
    • Image Size Reducer Pro v1.0.1.exe
    • Internet Download Manager V5.exe
    • K-Lite Mega Codec v5.5.1.exe
    • K-Lite Mega Codec v5.6.1 Portable.exe
    • Kaspersky AntiVirus 2010 crack.exe
    • LimeWire Pro v4.18.3.exe
    • MagicISO Magic ISO Maker v5.5.0276 Cracked.exe
    • McAfee Total Protection 2010.exe
    • Microsoft.Windows 7 ULTIMATE FINAL activator+keygen x86.exe
    • Minecraft Online play 476KB 2/14/2011 8:05:36 AM
    • Motorola, nokia, ericsson mobil phone tools.exe
    • Mp3 Splitter and Joiner Pro v3.48.exe
    • Myspace theme collection.exe
    • Nero 9 9.2.6.0 keygen.exe
    • Norton Anti-Virus 2010 crack.exe
    • Norton Internet Security 2010 crack.exe
    • PDF Unlocker v2.0.3.exe
    • PDF password remover (works with all acrobat reader).exe
    • PDF to Word Converter 3.0.exe
    • PDF-XChange Pro.exe
    • Power ISO v4.2 + keygen axxo.exe
    • RapidShare Killer AIO 2010.exe
    • Rapidshare Auto Downloader 3.8.exe
    • Sony Vegas Pro v9.0a incl crack.exe
    • Sophos antivirus updater bypass.exe
    • Starcraft2 REGION-UNLOCKER.exe
    • Starcraft2 SERVER-CHANGER.exe
    • Starcraft2 battle.net keys.txt.exe
    • Starcraft2.exe
    • Super Utilities Pro 2009 11.0.exe
    • Total Commander7 license+keygen.exe
    • Trojan Killer v2.9.4173.exe
    • Tuneup Ultilities 2010.exe
    • Twitter FriendAdder 2.1.1.exe
    • Uniblue RegistryBooster 2010.exe
    • VmWare 7.0 keygen.exe
    • VmWare keygen.exe
    • WinRAR v3.x keygen RaZoR.exe
    • Winamp.Pro.v7.33.PowerPack.Portable+installer.exe
    • Windows 2008 Enterprise Server VMWare Virtual Machine.exe
    • Windows 7 Ultimate keygen.exe
    • Windows XP PRO Corp SP3 valid-key generator.exe
    • Windows2008 keygen and activator.exe
    • YouTubeGet 5.4.exe
    • Youtube Music Downloader 1.0.exe

NOTES:
The dropped AUTORUN.INF is detected by Trend Micro as Mal_Otorun1.

  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_PROLAC.AA

    TROJ_HILOTI.SMAE
    TROJ_FAKEAV.SM2
    Mal_Otorun1

Step 3

Restart in Safe Mode

[ 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_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run
    • Adobe Updater 8.2 = %System%\AdobeAOM.exe
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer
    • gnome8ass = {month of execution}
  • In HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer
    • gnome8ass = {day of execution}
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Security Center
    • UACDisableNotify = 1
  • In HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\policies\system
    • EnableLUA = 0
  • In HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\SharedAccess\Parameters\FirewallPolicy\StandardProfile\AuthorizedApplications\List
    • %System%\AdobeAOM.exe = %System%\AdobeAOM.exe:*:Enabled:Explorer

Step 5

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
    • AdobeARM8
  • In HKEY_LOCAL_MACHINE\SOFTWARE
    • AdobeARM8

Step 6

Search and delete AUTORUN.INF files created by WORM_PROLAC.AA that contain these strings

[ Learn More ]
[autorun]
open=RECYCLER\S-1-6-21-2434476521-1645645927-702000330-1542\autorun.exe
icon=%SystemRoot%\system32\SHELL32.dll,4
action=Open folder to view files
shell\open=Open
shell\open\command=RECYCLER\S-1-6-21-2434476521-1645645927-702000330-1542\autorun.exe
shell\open\default=1

Step 7

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. [Drive Letter]:\RECYCLER

Step 8

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

Step 9

Scan your computer with your Trend Micro product to delete files detected as WORM_PROLAC.AA. 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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