Name :	Trojan-Downloader:W32/Agent.ETO
Size:	20992
Category:	Malware
Type:	Trojan-Dropper, Trojan-Downloader
Platform:	W32

Initially associated with the most recent PDF exploit malware run that we detect as Exploit:W32/AdobeReader.L, Agent.ETO normally arrives as a dropped/downloaded malware component by other malware running in the infected system.

Upon execution, it drops/downloads and executes several other trojans on the system.

Depending on the system OS version, the malware will overwrite any of the following files; with another trojan embedded in its resource section:


This newly created trojan is detected as Trojan-Downloader:W32/Agent.ACL . It is then executed as a Driver service using the Service Control Manager, thus further compromising the system.

The malware will then drop yet another malicious file in the system as:


This new driver will then be loaded and executed using a native call to NtLoadDriver after adjusting necessary system privileges needed to perform such commands. This new sys file is detected by F-Secure products as Trojan-Downloader:W32/Agent.DPE.

Due to this actions, the following registry associated with the malware will be created:


Note: %system% refers to the default windows System directory, it is usually c:\Windows\System32.

Such that the above registry becomes:


Lastly, using a hidden "browser" process (e.g. iexplore.exe, firefox.exe), it will inject another malware executable image in that process space to enable downloading other malicious files into the user system. Using this approach, it ensures that the downloader component will be able to do its job, since it is most likely that the user's internet browser is allowed to pass through the system firewall.

This injected image, is then responsible for downloading other files from remote servers and executing it in the compromised system. As of current testing, the download files is detected as: