Virus.Win32.CHIR.B-O

This Virus may be dropped by other malware.

It appends its codes to target files. It infects certain file types by inserting code in the said files.

It gathers target email addresses from the Windows Address Book (WAB).

Arrival Details

This Virus may be dropped by the following malware:

• PE_CHIR.B

Installation

This Virus drops the following copies of itself into the affected system:

• %System%\runouce.exe

(Note: %System% is the Windows system folder, where it usually is C:\Windows\System32 on all Windows operating system versions.)

It adds the following processes:

• {Malware Path}\{Malware Filename}.exe

It adds the following mutexes to ensure that only one of its copies runs at any one time:

• ChineseHacker-2

Autostart Technique

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

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
Windows\CurrentVersion\Run
Runonce = "%System%\runouce.exe"

File Infection

This Virus appends its codes to target files.

It infects files with the following file extensions by inserting code in the said files:

• .EXE
• .SCR
• .HTM
• .HTML

Propagation

This Virus gathers target email addresses from the Windows Address Book (WAB).

It exploits an unknown vulnerability in the following software so that the attachment automatically executes when the email message is read or previewed:

• MS01-020 - Incorrect MIME Header Can Cause IE to Execute E-mail Attachment

Other Details

This Virus does the following:

• Infected .EXE or .SCR files are detected as PE_CHIR.B.
• This file infector drops the following file on the folder location of the infected .HTM or .HTML file:
  
  • readme.eml - detected as HTML_IFRAME.DY
• It infects .HTM or .HTML by inserting a code that automatically executes the dropped README.EML when accessed. The infected .HTM or .HTML is detected as JS_NIMDA.A-1.
• It uses the following Simple Mail Transfer Protocol (SMTP) server:
  
  • {BLOCKED}.net.cn
• It uses it own Simple Mail Transfer Protocol (SMTP) engine to mass-mail messages with a copy of itself as an attachment. The email message contains the following details:
  TO: {Receipients Email Address}
  FROM: imissyou@{BLOCKED}.net.cn
  SUBJECT: {hostname} is comming!
  Attachment: pp.exe