Win32/Gimmiv is a trojan that gathers system information from the host computer on which it is installed. The trojan may delete itself after performing its data gathering routine. It consists of two components, TrojanSpy:Win32/Gimmiv.A and TrojanSpy:Win32/Gimmiv.A.dll.
may be installed onto an affected system through the successful exploitation of the vulnerability discussed in Security Bulletin MS08-067
. This exploit is detected as Exploit:Win32/MS08067.gen!A
. In the wild, we have observed Win32/Gimmiv
being distributed from a remote site as an executable with the file name 'n2.exe'.
drops a DLL as '<system folder
>\wbem\sysmgr.dll' (detected as 'TrojanSpy:Win32/Gimmiv.A.dll
'). The dropped DLL is registered to run as a service. After registering the service, TrojanSpy:Win32/Gimmiv
.A drops and runs a batch script that deletes the original Win32/Gimmiv
.A executable and then itself.
Collects System Information
While the service is running, it collects information about the computer in 10 minute intervals. The trojan gathers the following types of information:
Network Adapters / IP Addresses
Installed com objects
Recently opened documents
Outlook Express credentials
MSN Messenger credentials
Protected Storage credentials
The trojan then builds a large string containing gathered information and encrypts it. The trojan also creates a cookie named 'ac' that contains particular data.
Connects to Remote Host
The trojan generates a URL based on the operating system and antivirus information, in the following format:
<remote IP address>/test2.php?abc=<abc value>?def=<def value>
<remote IP address>/test2.php?abc=1?def=2
In the above, <abc value> is numeric and represents an associated type of antivirus application. The value for <def value> is also numeric and defines the operating system. The two values vary depending on the host computer.
The trojan issues a GET request to the constructed URL. The trojan also sends the cookie data to the remote server. At the time of this writing, no further code was downloaded.
As soon as the service finishes gathering information and contacting the remote web site, the trojan service stops, then drops and runs a batch script that unregisters the trojan service and deletes it.
Analysis by Aaron Putnam & Dan Kurc
There are no common symptoms associated with this threat. Alert notifications from installed antivirus software may be the only symptom(s).
Take the following steps to help prevent infection on your computer:
Enable a firewall on your computer.
Get the latest computer updates for all your installed software.
Use up-to-date antivirus software.
Limit user privileges on the computer.
Use caution when opening attachments and accepting file transfers.
Use caution when clicking on links to webpages.
Avoid downloading pirated software.
Protect yourself against social engineering attacks.
Use strong passwords.
Enable a firewall on your computer
Use a third-party firewall product or turn on the Microsoft Windows Internet Connection Firewall.
Get the latest computer updates
Updates help protect your computer from viruses, worms, and other threats as they are discovered. It is important to install updates for all the software that is installed in your computer. These are usually available from vendor websites.
You can use the Automatic Updates feature in Windows to automatically download future Microsoft security updates while your computer is on and connected to the Internet.
Use up-to-date antivirus software
Limit user privileges on the computer
Starting with Windows Vista and Windows 7, Microsoft introduced User Account Control (UAC), which, when enabled, allowed users to run with least user privileges. This scenario limits the possibility of attacks by malware and other threats that require administrative privileges to run.
You can configure UAC in your computer to meet your preferences:
Use caution when opening attachments and accepting file transfers
Exercise caution with email and attachments received from unknown sources, or received unexpectedly from known sources. Use extreme caution when accepting file transfers from known or unknown sources.
Use caution when clicking on links to webpages
Exercise caution with links to webpages that you receive from unknown sources, especially if the links are to a webpage that you are not familiar with, unsure of the destination of, or suspicious of. Malicious software may be installed in your computer simply by visiting a webpage with harmful content.
Avoid downloading pirated software
Threats may also be bundled with software and files that are available for download on various torrent sites. Downloading "cracked" or "pirated" software from these sites carries not only the risk of being infected with malware, but is also illegal. For more information, see 'The risks of obtaining and using pirated software
Protect yourself from social engineering attacks
While attackers may attempt to exploit vulnerabilities in hardware or software to compromise a computer, they also attempt to exploit vulnerabilities in human behavior to do the same. When an attacker attempts to take advantage of human behavior to persuade the affected user to perform an action of the attacker's choice, it is known as 'social engineering'. Essentially, social engineering is an attack against the human interface of the targeted computer. For more information, see 'What is social engineering?
Use strong passwords
Attackers may try to gain access to your Windows account by guessing your password. It is therefore important that you use a strong password – one that cannot be easily guessed by an attacker. A strong password is one that has at least eight characters, and combines letters, numbers, and symbols. For more information, see http://www.microsoft.com/protect/yourself/password/create.mspx