About BlackWormOver the last week, "Blackworm" infected more then 700,000 systems as measured using a counter web site used by the worm to track itself. This worm is different and more serious then other worms for a number of reasons. In particular, it will overwrite a user's files on February 3rd.
At this point, the worm will be detected by up to date anti virus signatures. In order to protect yourself from data loss on February 3rd, you should use current (Jan 23rd or later) anti virus signatures. Note, however, that the malware attempts to disable/remove any anti-virus software on the system (and does this every hour while the system is up), so if the machine was infected before signatures were deployed, obviously, that anti-virus software can't be expected to clean up the infection for you.
The following file types will be overwritten by the virus: DOC, XLS, MDE, MDB, PPT, PPS, RAR, PDF, PSD, DMP, ZIP. The files are overwritten with an error message( 'DATA Error [47 0F 94 93 F4 K5]').
We will try to post more detailed cleanup instructions later. However, it is likely that you will have to rebuild the system from scratch. Obtaining good backups is critical as a first step.
The first thing you should do is to update your anti virus signatures.
This page will be updated as new information becomes available. Please see the end of the page for references to other sites. Use only this url to link to this page: http://isc.sans.org/blackworm
NamingAs usual, this worm/virus has collected a number of names from various vendors. It is so far known as: Blackmal, Nyxem, MyWife, Tearec among other names. Update: we have been informed that the CME number will be 'CME-24'. cme.mitre.org should shortly list this number.
How would I get infected?The worm spreads via e-mail attachments or file shares. Once a system in your network is infected, it will try to infect all shared file systems it has access to. You may see a new "zip file" icon on your desktop.
What will BlackWorm do to my system?It will disable most anti virus products and delete them. The worm will e-mail itself using a variety of extensions and file names. It will add itself to the list of auto-start programs in your registry.
RemovalAnti virus vendors offer removal tools. Microsoft provides detailed instructions for manual removal. However, there are two important reasons to rebuild "from scratch":
Snort SignaturesJoe Stewart (Lurhq.com) provided the following snort signatures based on his analysis of the worm:
(for up to date rules, see bleedingsnort.org.
alert tcp any any -> any 80
alert tcp any any -> any 80
CreditsWe would like to thank the members of the TISF BlackWorm task force for analysis and coordination.
The task force emerged from the MWP/DA groups. This task force is now known as the TISF BlackWorm task force. involves many in the security (anti spam, CERTs, I will be teaching next: Intrusion Detection In-Depth - SANS Las Vegas Spring 2020
Jan 24th 2006
1 decade ago