Analysis by: Rhena Inocencio
 Modified by: Jimelle Monteser
ALIASES:

AdWare.Win32.Gator (Ikarus), AdWare.Win32.Gator.3102 (Kaspersky), Adware/Gator (Panda), AdWare.Gator (Sunbelt)

 PLATFORM:

Windows 2000, Windows Server 2003, Windows XP (32-bit, 64-bit), Windows Vista (32-bit, 64-bit), Windows 7 (32-bit, 64-bit)

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

  • Threat Type: Adware

  • Destructiveness: No

  • Encrypted: No

  • In the wild: Yes

  OVERVIEW

Infection Channel: Bundled with other malware

This adware arrives as a component bundled with malware/grayware packages. It may be manually installed by a user.

It does not have any propagation routine.

It does not have any backdoor routine.

It does not have any information-stealing capability.

This file contains a URL where it connects to possibly download other files. However, as of this writing, the said sites are inaccessible.

  TECHNICAL DETAILS

File Size: 3,428,903 bytes
File Type: EXE
Memory Resident: No
Initial Samples Received Date: 26 Nov 2009
Payload: Displays ads, Connects to URLs/IPs

Arrival Details

This adware arrives as a component bundled with malware/grayware packages.

It may be manually installed by a user.

Installation

This adware drops and executes the following files:

  • {User's Selected Installation Path}\DivX Pro Codec\gain_trickler_{random number}.exe - also detected as ADW_GATOR

It creates the following folders:

  • %User Temp%\fsg_tmp
  • %User Temp%\fsg_tmp\accum
  • %User Temp%\fsg_tmp\accum\Trickler

(Note: %User Temp% is the current user's Temp folder, which is usually C:\Documents and Settings\{user name}\Local Settings\Temp on Windows 2000, XP, and Server 2003, or C:\Users\{user name}\AppData\Local\Temp on Windows Vista and 7.)

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Gator.com\
Trickler
AppPath = "{User's Selected Installation Path}\DivX Pro Codec\gain_trickler_{random number}.exe"

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Trickler = "{User's Selected Installation Path}\DivX Pro Codec\gain_trickler_{random number}.exe"

Other System Modifications

This adware adds the following registry keys as part of its installation routine:

HKEY_LOCAL_MACHINE\SOFTWARE\Gator.com

HKEY_CLASSES_ROOT\CLSID\{CLSID}

HKEY_LOCAL_MACHINE\SOFTWARE\Gator.com\
Gator

HKEY_LOCAL_MACHINE\SOFTWARE\Gator.com\
Trickler

Propagation

This adware does not have any propagation routine.

Backdoor Routine

This adware does not have any backdoor routine.

Information Theft

This adware does not have any information-stealing capability.

Other Details

This adware connects to the following possibly malicious URL:

  • http://{BLOCKED}.{BLOCKED}r.com/machine.asp
  • http://{BLOCKED}.{BLOCKED}r.com/Cmd/client_log_event
  • http://{BLOCKED}.{BLOCKED}r.com/rs.dll?trk3
  • http://{BLOCKED}e.{BLOCKOED}r.com/download/trickler3.inf?{CLSID}

This file contains a URL where it connects to possibly download other files. As of this writing, this file contains the following URLs:

  • http://trickle.{BLOCKED}r.com/download

However, as of this writing, the said sites are inaccessible.

  SOLUTION

Minimum Scan Engine: 9.700
SSAPI PATTERN File: 1.205.00
SSAPI PATTERN Date: 04 Aug 2011

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

Identify and terminate files detected as ADW_GATOR

[ Learn More ]
  1. Windows Task Manager may not display all running processes. In this case, please use a third-party process viewer, preferably Process Explorer, to terminate the malware/grayware/spyware file. You may download the said tool here.
  2. If the detected file is displayed in either Windows Task Manager or Process Explorer but you cannot delete it, restart your computer in safe mode. To do this, refer to this link for the complete steps.
  3. If the detected file is not displayed in either Windows Task Manager or Process Explorer, continue doing the next steps.

Step 3

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_LOCAL_MACHINE\SOFTWARE
    • Gator.com
  • In HKEY_CLASSES_ROOT\CLSID
    • {CLSID}

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\CurrentVersion\Run
    • Trickler = "{User's Selected Installation Path}\DivX Pro Codec\gain_trickler_{random number}.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.
  • %User Temp%\fsg_tmp
  • %User Temp%\fsg_tmp\accum
  • %User Temp%\fsg_tmp\accum\Trickler

Step 6

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


Did this description help? Tell us how we did.