Sdbot.HWT 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:
passwords saved by certain Windows services. It sends the gathered information to a remote user by any available means: email, FTP, etc. It affects productivity, preventing tasks from being carried out: - In the affected computer:
it converts the computer into a platform for taking malicious action surreptitiously: spam sending, launch of Denial of Service attacks, malware distribution, etc.
- In the local network:
it generates a large amount of network activity and consumes bandwidth.
It reduces the security level of the computer:
it terminates processes belonging to security tools, such as antivirus programs and firewalls, leaving the computer defenseless against attacks from other malware; it awaits remote-control orders received through
IRC, FTP or other channels; it changes system permissions, decreasing the security level. Sdbot.HWT prevents access from programs to websites of several companies related with security tools (antivirus programs, firewalls, etc.). It uses stealth techniques to avoid being detected by the user: - It terminates processes corresponding to several security tools, such as antivirus programs and firewalls, to prevent detection.
- It injects itself in running processes.
- It deletes the original file from which it was run once it is installed on the computer.
- It modifies system permissions in order to hide itself.
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.
Sdbot.HWT 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.
- Peer-to-peer (P2P) file sharing programs: it makes copies of itself with enticing names in shared folders belonging to these programs. Other users of this type of networks then voluntarily download and run the infected files.
- IRC: It sends a copy of itself to all users connected to the channel to which the infected user is connected.
- Instant messaging: it sends links pointing to a copy of itself to all users included in the infected user's contacts list.
- Computer networks (shared resources): it creates copies of itself in shared network resources to which it has access.
|