Privacy and Legal Notice

CIAC INFORMATION BULLETIN

Q-076: Sober.X (Y) To Download New Code On or After Jan. 6

December 15, 2005 18:00 GMT
PROBLEM: The Sober.X (Y) worm is set to download new code from several sites starting on Jan. 6, 2006 and continuing indefinitely. The function of this new code is unknown at this time.
PLATFORM: All Windows platforms.
DAMAGE: This is a mass mailing worm and clogs mail servers with malicious messages. The operation of the new, downloaded code is unknown.
SOLUTION: Use updated antivirus software. Block access to the download sites and watch for connection attempts to those sites. Information on detection and removal is available on most antivirus sites.
VULNERABILITY
ASSESSMENT:		 The risk is MEDIUM. Sites with up-to-date antivirus programs will already have eliminated this worm. However, should a copy of the worm get by your antivirus scanning, the threat from the unknown downloads is unknown at this time and could be significant.
LINKS:  
  CIAC BULLETIN: http://www.ciac.org/ciac/bulletins/q076.shtml
  AV INFO:  Symantec
                      F-Secure		 http://www.symantec.com/avcenter/venc/data/w32.sober.x@mm.html
http://www.f-secure.com/v-descs/sober_y.shtml
http://www.f-secure.com/weblog/archives/archive-122005.html#00000729

The Sober.X or Y variants have a download capability to download new code starting on January 6, 2005 and continuing, at regular intervals, indefinitely. In order to hide the downloads and prevent the download URLs from being blocked, the downloads are from randomly generated URLs at the following free domain hosting sites.

For example, starting January 6 and continuing for 14 days, the URLs are,

At the end of fourteen days they will change to a new set of random URLs. While most of the connection attempts will be to non-existant URLs, the virus writer knows in advance what the URLs will be on any particular day. Thus, when he wants to upload new code, he simply registers the appropriate URL and uploads the new code.

It is unknown what this new code will do, and can be whatever the virus writer chooses. As such, sites should block access to these four domains starting on or before January 6 and continuing for several weeks. Sites should also watch for any connection attempts to these domains. Any connections to these domains, failed or otherwise, could point to an infected system. The domains are free hosting services in Germany and Austria and blocking them for a period of time should not impact your operations.

CIAC wishes to acknowledge the contributions of Verisign’s iDefense for the heads-up and list of download sites.
DOE-CIRC can be contacted at: 
    Voice:          +1 866-941-2472 (7 x 24)
    E-mail:          doecirc@doecirc.energy.gov
    World Wide Web:  http://www.doecirc.energy.gov/