There are no common symptoms associated with this threat - links are activated within IFrames while viewing web content on maliciously modified pages. Alert notifications from installed antivirus software may be the only symptoms.
What to do now
To detect and remove this threat and other malicious software that may be installed on your computer, run a full-system scan with an appropriate, up-to-date, security solution. The following Microsoft products detect and remove this threat:
An attacker may inject a client-side script into a vulnerable website, which then executes when a user visits the compromised page.
Furthermore, this detection was specifically identified linked to a Facebook comment spam URL, which leads to installation of Worm:Win32/Gamarue.A.