This is a script virus, and due to it's generic nature, there are no obvious symptoms. However, unusual internet traffic might be observed, as well as suspicious running processes and unwanted files.
Trojan.IFrame.BI is a small html code that opens a hidden browser window from the followind address:
These adresses contain other Trojan.IFrames that are chained togheter and redirect in the end to a number of exploit scripts that download and install trojans. Due to the complex chaining sistem that this Trojan.IFrame uses, the exploit scripts and the Trojans that they download may change.