Additional Details
Trojan-Downloader:W32/Small.DOG secretly downloads malware from a remote site to install and execute on the infected machine.
Distribution
Small.DOG may be delivered to the system in an infected file attachment accompanying German-language spam e-mail messages, such as below:
The attachment name used is Document.doc.exe. The attachment uses the Microsoft Word icon to disguise its executable nature and deceive the user into believing the attachment is a word document:
Execution
If the user executes the malware by clicking on the attachment, the Trojan creates a new instance of Svchost.exe using itself as the parameter.
It then drops the following file in the Windows System folder:
- {Copied filename of any file found on the Windows System directory}{Random character}.exe
Small.DOG attempts to connect to one of the following websites to download an encrypted text file:
- http://81.95.147.138/[...].txt
- http://docslv.com/gallery/bridge/[...].txt
- http://dreadwolf.net/[...].txt
- http://dynafilmes.com.br/imagens/3/[...].txt
- http://feldvossundpartner.de/images/[...].txt
- http://jobundfit.de/images/[...].txt
- http://leads4sales.co.uk/images/main/[...].txt
- http://mkpicture.de/images/[...].txt
- http://soloaguia.com/imagens/[...].txt
- http://spbfp.atlant.ru/sys/[...].txt
- http://spbfp.atlant.ru/sys/sys/[...].txt
- http://trendbusiness-at-home.de/images/[...].txt
It then decrypts the downloaded text file to reveal the following download path:
Small.DOG will then download and execute this file. The downloaded file is detected as
It installs the following registry entries as its autostart technique: