Downloader.IRS is a Trojan, which although seemingly inoffensive, can actually carry out attacks and intrusions.
- In the local network:
it generates a large amount of network activity and consumes bandwidth.
Downloader.IRS accesses several websites to download files, which it then runs. These can be any type of file, although they are normally malware.
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.
Downloader.IRS does not spread automatically using its own means. It needs an attacking user's intervention in order to reach the affected computer. The means of transmission used include, among others, floppy disks, CD-ROMs, email messages with attached files, Internet downloads, FTP, IRC channels, peer-to-peer (P2P) file sharing networks, etc.