Lineage.DOU 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.
It reduces the security level of the computer:
it changes the security settings of Internet Explorer, decreasing its security level.
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 terminates its own execution if it detects that it is being executed in a virtual machine environment, such as VMWare or VirtualPC.
- 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.
Lineage.DOU 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.