This FAQ was authored by members of the TISF BlackWorm task force (specifically the MWP / DA groups and the SANS ISC handlers).
The purpose is both to provide with a resource for concerned users and network administrators, as well as to be a level-headed myth-free source on the subject.
There seems to be excessive media hype as well as some “end-of-the-world” type predictions. The end of the world is not coming and most of us will still be here after February 3rd, but this is a serious issue for those who are infected and we didn’t manage to get to.
“300,000 infected users worldwide is not a terribly large amount when compared to previous worms like Sober or Mydoom. However, with this worm it isn’t the quantity of infected users, it is the destructive payload which is most concerning.”
— Joe Stewart, LURHQ.
CME-24 (BlackWorm) Users’ FAQ
Q. What is CME-24?
A. A mass emailing worm with a destructive payload.
for pointers to antivirus vendor descriptions and analyses relating to
Q. I hear about new viruses all the time–what makes this one a “big
A. This destructive virus will delete files from a number of popular
programs on February 3rd, and on the 3rd day of the month thereafter.
Files which may be deleted by the malware include files ending with the
extension of DOC, XLS, MDE, MDB, PPT, PPS, RAR, PDF, PSD, DMP, ZIP
Another factor that potentially makes this virus particularly noteworthy
is that it has seen broad distribution, with the estimated infected
machines in the hundreds of thousands.
Another factor that potentially makes this virus noteworthy is it’s self
defense mechanism. It closes windows if the caption has any of the
following strings in it. SYMANTEC, SCAN, KASPERSKY, VIRUS, MCAFEE, TREND
MICRO, NORTON, REMOVAL, or FIX. So many antivirus programs, scanners
etc… can not be updated or used on a system that is infected with
Q. You refer to this virus/worm as CME-24 — that’s not what *my*
antivirus vendor calls it. What other names does CME-24 use?
Vendor Malware Name
Avast! Win32:VB-CD [Wrm]
Command W32/Kapser.A@mm (exact)
Dr Web Win32.HLLM.Generic.391
F-Prot W32/Kapser.A@mm (exact)
Nod32 Win32/VB.NEI worm
Norman W32/Small.KI (W32/Small.KI@mm)
Panda W32/Tearec.A.worm (W32/MyWife.E.Worm)
Trend Micro WORM_GREW.A (Worm_BLUEWORM.E)
Q. What is CME?
A. CME provides single, common identifiers to new virus threats to reduce public confusions during malware outbreaks. CME
is not an attempt to solve the challenges involved with naming schemes for viruses and other forms of malware, but instead aims to facilitate the adoption of a shared, neutral indexing capability for malware.
Q. How do people get infected with CME-24?
A. Known methods for infection include infected email attachments and
network shares, however other mechanisms are also possible.
While some areas of the world appear to be more prone toward infection
than others, it appears that infected systems may be found in virtually
Q. What should I do to protect myself from getting infected with CME-24?
A. There is a number of things you can do:
Email attachments can contain viruses.
If your Internet Service Provider provides an email scanning service
subscribe to it.
Do not open attachments without first verifying that a trusted sender
intentionally sent it to you by asking them if they sent you an
Scan email attachments before opening them.
Do not open emails that claim to have naughty content. This is a common
trick used by email based viruses.
Backup your system!
You should be routinely making backups of your system. If you’ve been
putting it off, do it now. Backups will be a foundation that will help
you recover if your system does get infected. Backups are the most
reliable way to recover your data in the event of any data corruption
event, virus, malware, or hardware failure.
Note that your backup should be taken to non-rewritable media and/or
stored offline. If you do not make your backup to non-rewritable or
offline media, depending on the format you use; your backups might be at
risk from the malware’s destructive payload. This is particularly true
if you currently backup important files into a zipped archive, use
mirrored hard drives, or file shares none of those will protect you from
the destructive potential of this worm.
On new systems create recovery CDs. Many systems sold today do not come
with recovery CDs. The person purchasing the system is expected to
create them. Consult manufactures documentation for details.
Insure that you have antivirus software installed, and that you have
up-to-date antivirus definitions covering this particular malware. Do a
full system scan and confirm that you are not infected with CME-24 or
other malware. If you are infected, seek professional assistance to fix
the problem at once.
Do not unnecessarily share or mount shareable filesystems. Filesystems
should never be made available via weak or non-existant passwords.
Q. Help, I think I have been infected with CME-24. What should I do now?
A. If you have anti-virus software installed verify that it is up to
date. Check with your anti-virus vendor if you are unsure of how to do
this. If you had anti-virus software that you believe was disabled by
CME-24 you may have to uninstall it before re-installing it.
If you do not have anti-virus software installed there are several
anti-virus products that offer free or trial tools.
Av-test.org maintains a list of antivirus products.
and West Coast labs at
Some of these vendors offer free online scans as well. Be aware online
scanners usually require activex or java be enabled, may take a long
time and probably require admin privileges. Online scanners also do not
provide any long term protection against reinfection
If you’ve already been infected, you should seek professional help to
deal with that infection at once. Failure to deal with this malware
prior to the 3rd day of the month can result in data loss.
Q. Some very important file was trashed by the worm. I really need to
get the information that was in that file. I don’t have a clean backup.
What can I do? Can I get back at least part of that file?
A. Possibly, some file recovery tools might recover all or part of the
missing data. A data recovery service may be your be able to assist.
Q. Why would someone do something so tremendously stupid and
A. Unless the author comes out and tells us we may never know why.
Q. I run Windows Media Center Edition, Mac OS X, Linux, have a Treo,
etc. Is my system at risk? Or is this just a Windows XP thing?
A. This virus only affects Windows operating systems. It affects nearly
every version of windows.
Windows NT 3.x/4.0, 95, 2000, XP, Server 2003, ME and 98 are all
NETWORK ADMINISTRATORS PORTION
Q. I’m a mail server administrator. How can I protect my customers
from CME-24 and other malware?
A. There are several things you may want to do:
You may want to run a server-side antivirus program, or software to
strip or defang potentially dangerous attachments. Under Unix, ClamAV
ClamAV is one example of a free antivirus program that
you can run on your mail server; Procmail Email Sanitizer
is an example of a program that you can run to remove or defang
potentially hostile attachments. Under Windows there are several email
scanning antivirus programs available.
You should also endeavor to accept, process and resolve notifications
you may receive about infected customers. Confirm that you have a
working abuse@ address, a working postmaster@ address, and current
whois contact information for your domain(s). See
RFC 2142 for clarification.
If you have netblock(s) that have been assigned to you via SWIP or
whois, or an autonomous system number (ASN), please make sure that you
have current abuse reporting contact information defined in whois for
those resources as well.
If you operate an intrusion detection system, consider running
the Bleeding Snort rules that may help you to identify potentially
Bleeding Snort Rules
Educate your customers about security effective practices.
Site license an antivirus product and distribute it to your customers.
Encourage customers to routinely apply patches.
Encourage customers to use a software and/or hardware firewall.
Encourage customers to routinely backup their systems.
Where terms of service and applicable law permits, scan customer systems
for vulnerabilities and insure that customers get fixed or removed from
This document was prepared by the TISF BlackWorm task force which
includes many elements in the security communities including: anti spam
groups, CERTs, anti-virus teams, academia, law enforcement, and ISP’s.
The TISF BlackWorm task force would like to thank all the contributors
to this FAQ including: Members of the DA/MWP groups and The Internet
Storm Center handlers.