Banbra.GEM is a Trojan, which although seemingly inoffensive, can actually carry out attacks and intrusions.
It captures certain information entered or saved by the user, with the corresponding threat to privacy:
passwords saved by certain Windows services; keystrokes, in order to obtain information for accessing online banking services, passwords and other confidential information; email addresses.
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 displays pop-up windows; causes system slowdowns; 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.
- On remote sites: it mass mails junk mail (spam).
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.
Banbra.GEM redirects attempts to access web pages of certain banks to spoofed pages, with the aim of logging information entered by the user in these pages.
It uses stealth techniques to avoid being detected by the user:
- 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:
- 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.
Banbra.GEM 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.