Mydoom.M worm creates encrypted log files and sometimes sends them out instead of its own code due to a bug. As a result, the encryped data files are sent in a ZIP archive inside e-mails. The files have random (encrypted) content, they are about 1.1 or 1.2 kilobytes long. F-Secure Anti-Virus detects them as "I-Worm.Mydoom.m.log". Please delete messages and files that are detected as such by F-Secure Anti-Virus.
Allow F-Secure Anti-Virus to disinfect the relevant files.
For more general information on disinfection, please see Removal Instructions.