GgDoor.J is a backdoor that allows hackers to gain remote access to the affected computer in order to carry out actions that compromise user confidentiality and impede the tasks performed on the computer.
It captures certain information entered or saved by the user, with the corresponding threat to privacy:
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.
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 changes system permissions, decreasing the security level.
GgDoor.J accesses several websites to download files, which it then runs. These can be any type of file, although they are normally malware.
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 terminates processes corresponding to several security tools, such as antivirus programs and firewalls, to prevent detection.
- It injects itself in running processes.
GgDoor.J does not spread automatically using its own means. It needs an attacking user's intervention in order to reach the affected computer. The means of transmission used include, among others, floppy disks, CD-ROMs, email messages with attached files, Internet downloads, FTP, IRC channels, peer-to-peer (P2P) file sharing networks, etc.