Downloader.LMU 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:
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 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.
Downloader.LMU 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 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 uses several methods in order to avoid detection by antivirus companies:
- It prevents scanning tools from running, such as Windows Registry Editor, FileMonitor, etc.
Downloader.LMU 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.
- Instant messaging: it sends links pointing to a copy of itself to all users included in the infected user's contacts list.