'White Hat' Worm Tries to Remove Blaster
- By Scott Bekker
- August 19, 2003
In what appears to be a misguided attempt to do good, someone released a worm that exploits the same DCOM RPC vulnerability that enabled the Blaster worm but that attempts to automatically download the Microsoft patch and remove the Blaster worm if it's present.
Security vendors assigned the names Welchia, Blaster-D and Nachi to the worm. Symantec rated the worm a 4 in severity on its 5-point threat scale.
In addition to exploiting the DCOM RPC vulnerability patched in MS03-026, to target and modify Windows XP systems, Welchia also exploits the WebDAV vulnerability patched even earlier with MS03-007, to target Windows 2000 systems running IIS 5.0.
Symantec warns that the worm causes system instability due to an RPC service crash on Windows 2000 machines and compromises system security by installing a Trivial File Transfer Protocol (TFTP) server on all infected machines. Microsoft officials added that the worm generates excess network traffic.
Scott Bekker is editor in chief of Redmond Channel Partner magazine.