Encyclopedia entry
Updated:
May 25, 2009
| Published:
Feb 12, 2009
Aliases
Win32/FakeAv!generic
(CA)
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Trojan-Downloader.Win32.Delf.ppt
(Kaspersky)
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W32/Delf.CTYH
(Norman)
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Troj/Agent-IEI
(Sophos)
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Backdoor.Tidserv
(Symantec)
Alert Level
(?)
Severe
Antimalware protection details
Microsoft recommends that you download the
latest definitions
to get protected.
Detection last updated:
Definition: 1.49.1054.0
Released: Dec 28, 2008
|
|
Detection initially created:
Definition: 1.47.53.0
Released: Nov 08, 2008
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Summary
Win32/Chadem.A is a trojan that steals password details from an affected machine.
Symptoms
System Changes
The following system changes may indicate the presence of this malware:
-
The presence of the following file:
%Appdata%\winlogon.exe
%APPDATA%\Microsoft\Windows\winlogon.exe
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The presence of the following registry modification:
To key: HKCU\Software\Microsoft\Windows\CurrentVersion\Run
Adds value: "Microsoft Windows logon process"
With data: "%APPDATA%\Microsoft\Windows\winlogon.exe"
Technical Information (Analysis)
Win32/Chadem.A is a trojan that steals password details from an affected machine.
Installation
When executed Win32/Chadem.A copies itself to either %APPDATA%\winlogon.exe or %APPDATA%\Microsoft\Windows\winlogon.exe and executes that copy.
Note: %APPDATA% refers to a variable location that is determined by the malware by querying the Operating System. The default installation location for the %APPDATA% folder for Windows 2000, NT and XP is C:\Documents and Settings\<user>\Application Data; and for Vista is C:\Users\<user>\AppData.
It may also modify the registry to execute this copy at each Windows start:
To key: HKCU\Software\Microsoft\Windows\CurrentVersion\Run
Adds value: "Microsoft Windows logon process"
With data: "%APPDATA%\Microsoft\Windows\winlogon.exe"
Payload
Steals Sensitive Information
When installed the trojan listens to all network traffic looking for traffic associated with an FTP connection. If found the trojan posts the FTP server domain, the username and the password to a remote host.
The trojan posts information to the following IP addresses:
Additional Information
In the wild, we have observed Win32/Chadem.A being downloaded and installed on affected machines by
Win32/InternetAntivirus.
Analysis by Ray Roberts
Prevention
Take the following steps to help prevent infection on your system:
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Enable a firewall on your computer.
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Get the latest computer updates for all your installed software.
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Use up-to-date antivirus software.
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Use caution when opening attachments and accepting file transfers.
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Use caution when clicking on links to web pages.
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Avoid downloading pirated software.
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Protect yourself against social engineering attacks.
Enable a firewall on your computer
Use a third-party firewall product or turn on the Microsoft Windows Internet Connection Firewall.
To turn on the Windows Firewall in Windows Vista
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Click Start, and click Control Panel.
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Click Security.
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Click Turn Windows Firewall on or off.
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Select On.
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Click OK.
To turn on the Internet Connection Firewall in Windows XP
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Click Start, and click Control Panel.
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Click Network and Internet Connections. If you do not see Network and Internet Connections, click Switch to Category View.
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Click Change Windows Firewall Settings.
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Select On.
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Click OK.
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.
To turn on Automatic Updates in Windows Vista
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Click Start, and click Control Panel.
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Click System and Maintainance.
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Click Windows Updates.
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Select a setting. Microsoft recommends selecting Install updates automatically and choose a time that is convenient for you. If you do not choose Automatic, but you choose to be notified when updates are ready, a notification balloon appears when new downloads are available to install. Click the notification balloon to review and install the updates.
To turn on Automatic Updates in Windows XP
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Click Start, and click Control Panel.
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Click System.
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Click Automatic Updates.
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Select a setting. Microsoft recommends selecting Automatic. If you do not choose Automatic, but you choose to be notified when updates are ready, a notification balloon appears when new downloads are available to install. Click the notification balloon to review and install the updates.
Use up-to-date antivirus software
Most antivirus software can detect and prevent infection by known malicious software. To help protect you from infection, you should always run antivirus software that is updated with the latest signature files. Antivirus software is available from several sources. For more information,
see http://www.microsoft.com/protect/computer/viruses/vista.mspx.
Use caution when opening attachments and accepting file transfers
Exercise caution with e-mail 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 web pages
Exercise caution with links to web pages that you receive from unknown sources, especially if the links are to a web page that you are not familiar with or are suspicious of. Malicious software may be installed in your system simply by visiting a web page 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 in order to compromise a system, they also attempt to exploit vulnerabilities in human behavior in order to do the same. When an attacker attempts to take advantage of human behavior in order 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 system. For more information, see '
What is social engineering?'.
Recovery
