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TrojanSpy:Win32/Chadem.A


Win32/Chadem.A is a trojan that steals password details from an affected machine.


What to do now

Manual removal is not recommended for this threat. To detect and remove this threat and other malicious software that may have been installed, run a full-system scan with an up-to-date antivirus product such as the Microsoft Safety Scanner (http://go.microsoft.com/fwlink/?LinkId=212742). For more information, see http://www.microsoft.com/protect/computer/viruses/vista.mspx.

Threat behavior

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:
  • 70.87.136.2
  • 91.203.93.23
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

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
  • 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"

Prevention


Alert level: Severe
First detected by definition: 1.47.53.0
Latest detected by definition: 1.173.2181.0 and higher
First detected on: Nov 08, 2008
This entry was first published on: Feb 12, 2009
This entry was updated on: Apr 17, 2011

This threat is also detected as:
  • Win32/FakeAv!generic (CA)
  • Trojan-Downloader.Win32.Delf.ppt (Kaspersky)
  • W32/Delf.CTYH (Norman)
  • Troj/Agent-IEI (Sophos)
  • Backdoor.Tidserv (Symantec)