MS-DOS; Windows 2003/XP/2000/NT/ME/98/95/3.X; IIS

Mailbot.FS is a worm that spreads by copying itself, without infecting other files.

It captures certain information entered or saved by the user, with the corresponding threat to privacy: keystrokes, in order to obtain information for accessing online banking services, passwords and other confidential information; email addresses.

It affects productivity, preventing tasks from being carried out:

• In the affected computer: causes system slowdowns.

• In the local network: it generates a large amount of network activity and consumes bandwidth.

• On remote sites: it mass mails junk mail (spam).

It uses stealth techniques to avoid being detected by the user:

• It uses techniques included in its code to hide itself while it is active.
• It injects itself in running processes.
• It deletes the original file from which it was run once it is installed on the computer.

It uses several methods in order to avoid detection by antivirus companies:

• It terminates its own execution if it detects that it is being executed in a virtual machine environment, such as VMWare or VirtualPC.

Mailbot.FS uses the following propagation or distribution methods:

• Exploiting vulnerabilities with the intervention of the user: exploiting vulnerabilities in file formats or applications. To exploit them successfully it needs the intervention of the user: opening files, viewing malicious web pages, reading emails, etc.
• Email: sending emails that include a copy of itself as an attachment. The computer is infected when the attachment is run.