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  3. W32.Yaha.U@mm

W32.Yaha.U@mm

Risk Level 1: Very Low

Discovered:
July 1, 2003
Updated:
February 13, 2007 12:03:11 PM
Also Known As:
I-Worm.Lentis.gen [KAV]
Type:
Worm
Systems Affected:
Windows 2000, Windows 95, Windows 98, Windows Me, Windows NT, Windows XP


The W32.Yaha.U@mm worm:
  • Is a variant of W32.Yaha.J@mm.
  • Terminates some antivirus and firewall processes.
  • Uses its own SMTP engine to email itself to all the contacts in the Windows Address Book, MSN Messenger, .NET Messenger, Yahoo Pager, and in all the files whose extensions contain the letters HT.

The email message has a randomly chosen subject line, message, and attachment name. The attachment will have a .com, .exe, or .scr file extension.

This worm is written in the Microsoft C++ language and is compressed with ASPack.

Antivirus Protection Dates

  • Initial Rapid Release version July 1, 2003
  • Latest Rapid Release version September 28, 2010 revision 054
  • Initial Daily Certified version July 1, 2003
  • Latest Daily Certified version September 28, 2010 revision 036
  • Initial Weekly Certified release date July 2, 2003
Click here for a more detailed description of Rapid Release and Daily Certified virus definitions.

Threat Assessment

Wild

  • Wild Level: Low
  • Number of Infections: 0 - 49
  • Number of Sites: 0 - 2
  • Geographical Distribution: Low
  • Threat Containment: Easy
  • Removal: Moderate

Damage

  • Damage Level: Medium

Distribution

  • Distribution Level: High
Writeup By: Kaoru Hayashi

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