McAfee > Theat Center > Virus Detail Page

Overview

This is a trojan detection. Unlike viruses, trojans do not self-replicate. They are spread manually, often under the premise that they are beneficial or wanted. The most common installation methods involve system or security exploitation, and unsuspecting users manually executing unknown programs. Distribution channels include email, malicious or hacked web pages, Internet Relay Chat (IRC), peer-to-peer networks, etc.

Characteristics

-- Update October 20, 2009 --
The risk assessment of this threat has been updated to Low-Profiled due to media attention at: http://www.theregister.co.uk/2009/10/16/gumblar_mass_web_compromise/

--

Updated: October 19th 2009

New samples have been found related to this threat, that may be downloaded on a system as a result of malicious web based scripts. These sample when executed, drops a DLL file into the %User Profile% folder with a random name. At the time of our testing, the following file was created:

• %User Profile%\xrsgmrm.old

A registry key is created which creates the following registry key. This key usually defines the windows dynamic-link library for applications. Hence any application which calls a sound device would load this DLL. The injected DLL if loaded into applications such as regedit, notepad.exe, etc prevents them from showing a GUI.

• HKLM\Software\Microsoft\Windows NT\CurrentVersion\Drivers32
• midi9 = "%User Profile%\Desktop\..\xrsgmrm.old 0yAAAAAAAA"

Other regsitry modifications made  include:

• HKLM\Software\Microsoft\Windows NT\CurrentVersion\Windows
• LoadAppInit_DLLs = 0x00000001
• HKLM\System\ControlSet001\Control\Session Manager
• PendingFileRenameOperations = Path To Original dropped file
• HKLM\Software\Microsoft\Windows NT\CurrentVersion\Windows
• AppInit_DLLs = ""

======================================================================

This Trojan injects threads into Internet Explorer. The injected threads create outbound TCP connections to the following IPs to download a file:

78.110.175.15
66.116.131.209
76.163.147.77
76.163.124.43
76.162.92.47
76.163.202.9
64.17.143.140
71.18.215.20
81.18.249.216
76.163.46.215
94.247.2.58
195.24.76.250

The threads repeatedly try to connect to these IPs using hunderds of increasing port numbers, hoping to bypass firewall rules that allow outbound connections for valid services.

At the time of this testing, the file requested was not being served by the above IPs.

Symptoms

The presence of outbound connections to the mentioned IPs.

Method of Infection

Trojans do not self-replicate. They are spread manually, often under the premise that the executable is something beneficial. Distribution channels include IRC, peer-to-peer networks, newsgroup postings, etc. However they may be downloaded by other viruses and/or Trojans to be installed on the user's system.

Many of these are mass spammed by the author to entice people into double-clicking on them. Alternately they may be installed by visiting a malicious web page (either by clicking on a link, or by the website hosting a scripted exploit which installs the Trojan onto the user's system with no user interaction).

Removal

All Users:
Use current engine and DAT files for detection and removal.

Modifications made to the system Registry and/or INI files for the purposes of hooking system startup, will be successfully removed if cleaning with the recommended engine and DAT combination (or higher).

Additional Windows ME/XP removal considerations

Variants

Variants

N/A

All Information

Overview -

This is a trojan detection. Unlike viruses, trojans do not self-replicate. They are spread manually, often under the premise that they are beneficial or wanted. The most common installation methods involve system or security exploitation, and unsuspecting users manually executing unknown programs. Distribution channels include email, malicious or hacked web pages, Internet Relay Chat (IRC), peer-to-peer networks, etc.

Characteristics

Characteristics -

-- Update October 20, 2009 --
The risk assessment of this threat has been updated to Low-Profiled due to media attention at: http://www.theregister.co.uk/2009/10/16/gumblar_mass_web_compromise/

--

Updated: October 19th 2009

New samples have been found related to this threat, that may be downloaded on a system as a result of malicious web based scripts. These sample when executed, drops a DLL file into the %User Profile% folder with a random name. At the time of our testing, the following file was created:

• %User Profile%\xrsgmrm.old

A registry key is created which creates the following registry key. This key usually defines the windows dynamic-link library for applications. Hence any application which calls a sound device would load this DLL. The injected DLL if loaded into applications such as regedit, notepad.exe, etc prevents them from showing a GUI.

• HKLM\Software\Microsoft\Windows NT\CurrentVersion\Drivers32
• midi9 = "%User Profile%\Desktop\..\xrsgmrm.old 0yAAAAAAAA"

Other regsitry modifications made  include:

• HKLM\Software\Microsoft\Windows NT\CurrentVersion\Windows
• LoadAppInit_DLLs = 0x00000001
• HKLM\System\ControlSet001\Control\Session Manager
• PendingFileRenameOperations = Path To Original dropped file
• HKLM\Software\Microsoft\Windows NT\CurrentVersion\Windows
• AppInit_DLLs = ""

======================================================================

This Trojan injects threads into Internet Explorer. The injected threads create outbound TCP connections to the following IPs to download a file:

78.110.175.15
66.116.131.209
76.163.147.77
76.163.124.43
76.162.92.47
76.163.202.9
64.17.143.140
71.18.215.20
81.18.249.216
76.163.46.215
94.247.2.58
195.24.76.250

The threads repeatedly try to connect to these IPs using hunderds of increasing port numbers, hoping to bypass firewall rules that allow outbound connections for valid services.

At the time of this testing, the file requested was not being served by the above IPs.

Symptoms

Symptoms -

The presence of outbound connections to the mentioned IPs.

Method of Infection

Method of Infection -

Trojans do not self-replicate. They are spread manually, often under the premise that the executable is something beneficial. Distribution channels include IRC, peer-to-peer networks, newsgroup postings, etc. However they may be downloaded by other viruses and/or Trojans to be installed on the user's system.

Many of these are mass spammed by the author to entice people into double-clicking on them. Alternately they may be installed by visiting a malicious web page (either by clicking on a link, or by the website hosting a scripted exploit which installs the Trojan onto the user's system with no user interaction).

Removal -

Removal -

All Users:
Use current engine and DAT files for detection and removal.

Modifications made to the system Registry and/or INI files for the purposes of hooking system startup, will be successfully removed if cleaning with the recommended engine and DAT combination (or higher).

Additional Windows ME/XP removal considerations

Variants

Variants -

N/A