I recently noticed that my harddrive was ‘filling up’ for no apparent reason. I have a personal desktop computer with Windows 7 & I use Firefox, I keep very little as far as files, pictures, etc; & just went through transferring everything I did want to keep to memory stix just to be on the ‘safe side’. I ran my Avast scan to see what resulted & it picked up a file that it said it couldn’t/wouldn’t open because it was a compression bomb. I tried to find the file & access it but could not ( I couldn’t ‘type’ the letters/symbols at the end of the address, tried to find them with my alt key but no luck) ). I have also scanned my system with Malwarebytes & it is not picking up anything at all. Whatever this is, it is taking up a large chunk of my harddrive & has increased then decreased a little each day. This file is some type of ‘session storage’ log from Google Chrome, I don’t have this browser on my computer. Any suggestions ?
A compression bomb is packed so tight that it’s large file cannot be scanned until accessed.
Once it begins to unpack avast will then scan the file. When the unpacking is done and the file
is again accessed then avast will scan it again.
- Decompression Bomb, a file that is highly compressed, which could be very large when decompressed. This used to be a tactic long ago to swamp the system.
The name really is the most dangerous thing about this and I wish they would change it or simply not report it, a real PITA.
These highly compressed files are generally ‘archive’ files which are inert, don’t present an immediate risk until they are unpacked. If you happen to select ‘All packers’ in your on-demand scans then you are more likely to come across this type of thing. Personally it is a waste of time scanning ‘all packers’ and that is why it isn’t enabled by default.
I find Character Map useful in cases like that, and added a shortcut to it to my desktop. Assuming you can recognize the character when you see it, CM lets you copy and paste.