The Zindos worm used the backdoor that was installed by the Mydoom.M worm, that spread earlier. Since Zindos had no other infection vector, so it could only spread to computers that were infected with Mydoom.M earlier. It even used a list of infected computers, collected by Mydoom. I suppose the idea was to use the mass-mailing worm to pave way to the payload for rapid distribution later. The Zindos code had not much to do, just go straight through the list of already compromised computers and copy itself there through the backdoor. Zindos is a network worm which spreads with the help of the Mydoom.M mass-mailing worm. For more information, see Mydoom.M.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
Mydoom.M plants a backdoor that scans for other systems with the same backdoor. Zindos uses the backdoor and its target list to spread. The payload is a Distributed Denial-of-Service (DDOS) attack against www.microsoft.com.
Zindos first arrives through the Mydoom.M backdoor. When uploaded to the victim, the worm file is dropped to the TEMP folder with a random name. The file is added to the registry as either of
[HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Run] "Tray" = "%TEMP%\.exe"
To propagate Zindos uses the list of compromised computers collected by the Mydoom.M backdoor. The worm goes through the list and uploads itself with the corresponding command through the backdoor.
The payload of Zindos is a Distributed Denial-of-Service routine that downloads http://www.microsoft.com/ in an infinite loop with 50ms delays.