MyDoom.K worm variant appeared on May 21st, 2004. It is functionally similar to MyDoom.E variant, but does not spread to Kazaa file sharing network and does not perform a DoS (Denial of Service) attack. The worm drops a backdoor component that listens on port 3127.
Based on the settings of your F-Secure security product, it will either move the file to the quarantine where it cannot spread or cause harm, or remove it.
A False Positive is when a file is incorrectly detected as harmful, usually because its code or behavior resembles known harmful programs. A False Positive will usually be fixed in a subsequent database update without any action needed on your part. If you wish, you may also:
Check for the latest database updates
First check if your F-Secure security program is using the latest updates, then try scanning the file again.
Submit a sample
After checking, if you still believe the file is incorrectly detected, you can submit a sample of it for re-analysis.
Note: If the file was moved to quarantine, you need to collect the file from quarantine before you can submit it.
Exclude a file from further scanning
If you are certain that the file is safe and want to continue using it, you can exclude it from further scanning by the F-Secure security product.
Note: You need administrative rights to change the settings.
MyDoom.K worm's file is a PE executable 50176 bytes long compressed with a modified UPX file compressor. The backdoor DLL is a 4608 bytes long, also compressed with a modified UPX file compressor.
When the worm's file is run, it creates a separate thread that generates garbage data file and then opens it with Notepad. Then this thread terminates.
After that the worm drops SHIMGAPI.DLL file into Windows System folder. This file is a backdoor (hacker's remote access) component. It is started as a thread of Explorer from the following Registry key:
Finally the worm installs itself to system. It copies itself as RUNDLL6.EXE file to Windows System directory and creates a startup key for this file in the Registry:
where %winsysdir% represents Windows System directory name.
Additionally the worm deletes the following Registry keys:
The worm spreads itself in email messages. To locate email addresses to spread to, the worm reads Address Book file name from the Registry:
Then it browses through the Address Book file and collects email addresses from there. Additionally the worm looks for email addresses in files with the following extensions:
The worm avoids using email addresses that contain the following substrings:
The worm can fake the sender's email address. It composes email addresses from 2 parts: user name and domain name. Here is the list of user names that the worm uses:
Here is the list of domain names that the worm uses:
The subject for the infected message is selected from the following variants:
The body of the infected message can contain one of the following:
The attachment name can be one of the following:
The attachment can have 2 extensions. In such case the first extension can be:
And the second or the only extension can be:
The worm can also send itseld inside a ZIP archive.
The worm drops a backdoor component that starts as a thread of Explorer and listens to port 3127 for commands from remote hackers.
Additionally the worm tries to connect to 'sipper112.netfirms.com' website. At the moment of creation of this description the site was not accessible because it exceeded its its daily bandwidth limit.