Hilarous harddrive space taken by avast

[feeber]

Hey guys
recently a friend of mine got himself a new pc - but as he is who he is, he didnt install any antivirus. happly for him very first virus he caught reminded him of that mistake in very delicate way, but still helloads of spam, adds, and other crap got onto his computer. we managed to resque it fully, thanks to scanning by avast mostly, but today ive noticed something terrifying - avast folder is taking waay to much space than it should. Ive noticed his partition C (which is supposed to hold just windows, office etc) has 2 gbs left from almost 100gb space. well, by some further investigation ive got to this:
http://img689.imageshack.us/img689/5247/gx30.jpg

and following, to that:



could someone tell me- why is this happening, will it go off, what should i delete, or can i just throw the whole log folder to bin right now?
sorry for eventual english mistakes, as u can see by screenshots its not my main language

Edit: ive found the topic about avast taking 5gb of space (http://forum.avast.com/index.php?topic=136588.0) and did as instructed, but the repair tool didnt help at all.

[bobo1]

By the looks of your image is the operating system windows vista or 7 or 8?
Have you tried right clicking c drive. select properties and do disk cleanup?

Looks like the so called virus has filled your hard drive with junk files.

TMP.  BAK. OLD EXTENSIONS FILES CAN BE DELETED OK.

Download malware bytes free and run antispyware test and report back to us what it finds.

[DavidR]

@ bobo1
They are in the avast log folder and are almost certainly dump files.

@ feeber
Are the files that are taking the majority of space, in the same file format as in the image in the topic link you gave (unp9999999.mdmp) ?

These dump files are created when avast experiences a problem, this may not be a problem that is reported to the screen.

Are you getting any avast errors displayed to the screen ?

The .mdmp files can safely be deleted, but keep a couple as they could provide useful information if one of the developers picks up on this topic.

If the repair hasn't resolved the problem with avast that is generating the dump files, then it would probably be best to do a clean reinstall of avast.

Of course there is a possibility that the infection wasn't fully removed and this is compromising avast, resulting in these dumps.