When I booted up my computer today I had this popup showing. I have been using both steam and avast for a few years and I havent had this problem before. I searched for a bit on the forums and apperantly this happens pretty commonly after certain updates so I sent the file to virus lab from the virus chest.
I never use this pc other than gaming so I assume this is false positive as other past threads suggest. Do I have to do anything else than waiting for it to be fixed?
Just had this as well when I booted up steam, have a feeling its a false but would like to be sure.
Also after a steam update and reload I got this one AppOverlay.dll.1349564866
Welcome to the Forums.
Yes, Just wait. Once in a while ( after a VPS update ) scan file from virus chest. If it is not detected, you can restore it.
Welcome to Avast! Forum.
Since your file is not the same, it would have been better to open your own topic.
If you have it in the virus chest, follow the same procedure and send it to Avast! lab.
Just got this aswell, scared the living daylights out of me lol!
http://i50.tinypic.com/ayksuo.png
Since we both got it, i’d go for the FP option.
Yes I see the AppOverlay.dll infected as well so I assume it is also false positive and related with the steamservice.dll. But I will wait and see what happens just in case.
Alpha32.
Just got this aswell, scared the living daylights out of me lol!
Thank God it was not the old Avast! v.4 with its nuclear siren alert pop-up. You will be in ICU right now ;D.
Kidding appart.
I am not saying this is a F/P. Send files to Avast! lab and wait for an answer.
Submitted my file of SteamServices.dll to the virus lab a few hours ago however i’m like 99.9% it’s FP considering how many people it’s affecting who all happen to have Avast (topic’s on the Steam forums, this topic, yahoo answers and a few gaming sites which have huge communities).
Well I’ve got mine doing the whole bypass scan at the moment, first time ever it’s had an issue with steam, found the steam service.dll then alerted as part of the bypass scan that Appoverlay.dll was also infected with win32:Trojan-gen, so will let the scan finish and later reinstall steam if need be…
The latest update seemed to fix it, but I am doing a re-scan just to be sure.
Ok now Avast says friendsUI.dll has the same infection. Sent it to virus labs as well. Hopefully this will get sorted soon so I can actually start steam up 
I think avast made another update a while ago and now everything looks clean :).
Happened to me yesterday as well and i found 4 suspected files, i also ran a boot up scan and it had a lot of corrupted steam files and a few others but im not sure if they were steam or not, is this the same for you?
Joshg94.
Since it seems these files are not the same as the ones mentioned above, By the way they are not being detected by Avast! any longer, you need to send your files to Avast! virus lab for analysis. it is the only way to be sure they are F/P. About the corrupted files. It is common for Avast to detected or inform zip, rar, and cab files as corrupted because of some inability to read them correctly.