TR/Agent.7168.69

that virus name seems to be only used by Avira (classified as a trojan/rootkit) but they've feck all information on their site about what it actually is... usually AV websites include a profile of the threat including what other AV engines call it.

you could try a rootkit remover: http://www.sophos.com/products/free-tools/sophos-anti-rootkit.html

but without more details on what the threat actually is I cant honestly recommend any course of action based on what you've supplied.

as a general procedure try:
boot in safemode and run stinger: http://vil.nai.com/vil/stinger/

if its a windows system you could try booting to the recovery console and running a repair on the system files (then re-applying any service packs etc) to repair/renew any overwritten/modified dlls. - honestly , I DONT RECOMMEND THIS except as a last resort before you wpe and re-install


Malware Bytes is very good but I find it misses stuff sometimes. always run a second Anti Spyware tool. Spybot Search and Destroy is pretty good - though I suspect it deliberately reports a few false positives to boost how "effective" you think it is...