Also known as: TROJ_BANLOAD.BJT (Trend), TROJ_PWS-Banker.dldr (McAfee), TROJ_TrojanDownloader:Win32/Small (MS OneCare), Trojan-Downloader.Win32.Delf.asr (Kaspersky)
Win32/SillyDl.DUS is a downloading trojan.
Win32/SillyDl variants may be installed via Internet Explorer exploits when users visit malicious web pages; other trojan downloaders or components; or they may be packaged with software that the user has chosen to install.
A downloader is a program that automatically downloads and runs and/or installs other software without the user's knowledge or permission.
In addition to downloading and installing other software, it may download updated versions of itself.
Win32/SillyDl variants may download other trojans, or non-malicious programs such as adware. At any given moment in time, the program(s) it attempts to download may be changed or updated, or may be unavailable altogether. This family of trojans usually downloads using HTTP.