DuiskBot.A.worm 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.
It sends the gathered information to a remote user by any available means: email, FTP, etc.
- In the local network:
it generates a large amount of network activity and consumes bandwidth; it carries out denial of service attacks against
file servers and web servers or databases on the local network.
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 changes the security settings of Internet Explorer, decreasing its security level; it notifies the attacker that the computer has been compromised and is ready to be used maliciously; it listens on open ports in order to control the computer remotely.
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 uses several methods in order to avoid detection by antivirus companies:
- It prevents scanning tools from running, such as Windows Registry Editor, FileMonitor, etc.
- It terminates its own execution if it detects that a memory dump program is running, such as Procdump.
- Its code is encrypted and it is only decrypted when it is going to run. Because of this, its code is not legible through a memory dump.
- It terminates its own execution if it detects that a debugging program is active.
DuiskBot.A.worm 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.
- 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.