Specificially https://en.z-lib.gs/
I downloaded some pdfs from there and according to virustotal and some pdf online scanner i tried, they have something possibly malicious going on in them. I already deleted them but i opened them in firefox pdf reader. I dont have acrobat installed.
Scanning my system with malwarebytes now, but nothing is finding anything wrong and I havent seen any suspicious activity.
Here is the analysis itself.
I’m starting to panic, please help if you have any advice
Thank you all, you are wonderful people
Just for future highly recommend to use this for future PDFs https://github.com/freedomofpress/dangerzone
Is this in the megathread? If not, it should be.
Adding this as the second app alrey this year that I’ll install simply based on the name alone (only drams being the other).
I have downloaded hundreds of documents from Z-library and LibraryGenesis and never had an issue with a single one of them.
That virus total scan shows free and clear, it has some warnings about there being external links inside the doc afaik (VT very broken on mobile so i can’t understand the report well), but that’s really fringe edge stuff to actually be “dangerous”. You’re over-awfulizing the danger.
If it is new malware, scanners wouldnt pick up on it.
On behavior tab there is tons of stuff. Shouldnt there be none? I dont know too much about virustotals results mean, but doesnt the mitre thing mean it could potentially do something like that?If it is new malware, scanners wouldnt pick up on it.
Actually they do often pick up on it, unless it is a very novel attack vector (and probably not something you’d find on a pirate site). Malware often follows very predictable code execution patterns of communicating with outside IP’S and modifying other executables, and these are things that can be detected by most AV.
On behavior tab there is tons of stuff. Shouldnt there be none?
There will never be none. it’s all listed as low or no risk/informational only anyway, which goes back to the pattern recognition thing.
VT is listing things that the file has done during viewing. ALL things. This stuff might or might not be a concern, whether or not it’s a known attack or pattern of malicious behavior. If you are a legit security analyst you can use the behavior data to see what files its touching and stuff and understand good and bad security design. Like, the only actual yellow warning is… it apparently looked at Google dns. Which is something any browser pdf viewer will do.
Oh. The other thing I forgot to mention, is every submission to Z-Lib goes through an approval process where a certain number of community contributors have to review the document and make sure it’s legible, safe, and valid. I know, because I’ve submitted stuff before, it takes quite a few days to go live. It’s not just random bad actors shotgunning stuff onto the site.
thank you, that puts my mind at ease somewhat
That virultotal report looks completely fine to me, including the behavior tab.
Regardless, imagine what would happen if the firefox pdf reader was vulnerable to a well-known attack (of course there probably exist 0 days but they wouldn’t be burned on you). Any attacker could simply link you a PDF and you’d be infected simply for clicking the link? If this was true, people would stop using firefox because it would be insecure.
None of the scanners on VirusTotal picked up anything. What makes you think the PDF if malicious?
the behaviour tab, also based on this https://scan.tylabs.com/ website.
The link to Z-Library itself is one of the legitimate ones from what I know so I wouldn’t worry on that side too much.
PDFs have a few exploits that could infect a system. However they are rare and not efficient especially if the intent is to infect as much machines as possible.
If you don’t have much technical knowledge to analyze the files yourself, I would recommend you open the PDFs in Virtual Machines without any acess to the internet or opening the files only when you have disconected your device from any acess to the internet.
Tools like the one mentionned by someone else in the comments would be good to prevent from having to worry about a potentially malicious PDF. Various tools are around to convert a malicious file lile PDFs into regular “trusted” PDFs (said tools flattens everything making it impossible to select text or click any URIs included). I would look up the trustworthiness of some of those tools first (to not try and avoid malwares by installing one).
That was way too long of a comment but I hope it could ease some of your worries.
1lib.sk is the link I get from the telegram bot, I trust it
