This type of trojan secretly downloads malicious files from a remote server, then installs and executes the files.
Once detected, the F-Secure security product will automatically disinfect the suspect file by either deleting it or renaming it.
This trojan-downloader appears to be related to a distribution of spam e-mails currently under way as of 5 April 2011, as hundreds of samples were submitted to our analysis systems in the last 24 hrs.
The spammed e-mail uses a social engineering attack to lure the recipient into clicking on an attached executable file. This attachment is actually the trojan-downloader, disguised as a legitimate document. The attachment uses a PDF file icon and the filename 'dhl.exe' to further disguise itself.
On clicking the file, the trojan-downloader is executed and creates a dummy svchost.exe process. It then injects a thread that downloads and executes a file from:
- h t t p : / / puskovayaustanovka.ru/pusk[...].exe
At the time of writing, the domain is blocked by the Browsing Protection feature of our product.