Stupid question but is it possible to get a virus from an MKV file.

Thebay@lemmings.world to Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ@lemmy.dbzer0.com – 71 points –

Stupid question but is it possible to get a virus from an MKV file that is less than 24 hours old. I was streamed using VLC version 3.0.20 form the repose on Linux.

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Every once in a while security researchers would discover sophisticated exploits that would allow malwares to take over your computer via multimedia files, but those are actually rarely exploited in the wild by run off the mill malwares.

Unless you're an important person being targeted by hackers and three letter agencies, your biggest source of threat is running infected programs from untrusted sources, e.g. cracks downloaded from random torrents or warez sites, shady sites serving ads that trick you to run some executables, etc.

I really hate to be "that person", but..........it's "run of the mill", not "run off the mill", friend.

It's a term from the late 1800s that refers to "manufactured goods not graded or sorted for quality—that is, a mill's products before they've been separated according to what will sell for how much." (Source for quote: https://www.merriam-webster.com/wordplay/where-does-run-of-the-mill-come-from)

Seriously, I'm not trying to be a grammar nazi here. Unless of course that was just autocorrect being a dick, in which case I'll go walk off a cliff now... :/

Wild that people have ESCAPED VMs… but yeah that’s not happening on my boring ass’s computer

Me with SELinux hardened podman in a VM, running an offline Minecraft server😳

Definitely no, viruses need 48-72 hours of incubation before the .mkv host becomes contagious. If the file is <24 hours old, I'd look for another source.

If you're worried your computer might be infected, you should consider swapping your case LEDs with UV lights to purify your system.

someone please correct me if I’m wrong but I believe that for it to be possible, the application that plays the mkv file would have to have a remote execution exploit and the code for the virus would be executed through the player. the player would be required to have elevated privileges. I think this is exceptionally unlikely for vlc

The player does not have to be elevated. With an unelevated player the file exploiting such a vuln would be able to execute code with the privileges and access of the player

You’re probably fine it’s extremely unlikely. Dont trust emails that say they recorded you wanking its a scam

Like someone else said, it's unlikely. However it is possible but it would need to exploit your media player (VLC) and/or your OS. As long as your source is trustworthy you shouldn't have to worry, that's why the megathread is there.

The mkv file wasn't form a trustworthy source.

As others have said, it’s technically possible, but it would extremely difficult and would require coordinating a lot of different variables which is extremely unlikely. I’m not sure there’s actually ever been an example of this type of attack outside of a lab.

Absolutely yes. Even if it is not disguised executable.

It could contain an exploit which targets the video player you are opening it with.

There's imho no stupid questions regarding personal cyber-security. There are only things we don't know yet.

In general media files can be formed in a way to trigger some bug in the media player, sometimes in ways that allow to overflow buffers and start ROP chaining.

About 8 years ago there was this media file going around crashing any iPhones that tried to play it with the integrated player.

Of course crashing is way easier than code execution. So overall your scenario is unlikely. VLC also does not yet know of any issues with 3.0.20: https://www.videolan.org/security/

When was the last time VLC paid $50K USD for a proper security audit?

Probably never?

Next you're gonna be judging cars on their ability to float.

Open source follows an entirely different risk model (and arguably much more effective than throwing money at greedy companies)

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Afaik, it's possible for any file to be infected with a virus. Videos themselves can be, and .MKV is a container of other files (video, audio, subtitles). The video source, audio source or even .txt containing the subtitles could be a malicious virus inside the container.

In theory, you could make a fake executable with the mkv file extension on a unix system, by making it a shell script with a bunch of garbage data at the end, marking it executable, and distributing it with a tarball. But the chances someone will do that is insanely low.

Also it has caveats:

  1. It'd rely on your double clicking it, and having your file manager not warning you about it.
  2. Video players wouldn't run the shell script code, if it'd run the file at all.

Not really, but you can get a virus from movie.mkv.exe, which will probably show up in windows as "movie.mkv" but will actually run a program.

That being said, I've never actually seen this in the wild and it was mainly talked about in the mp3 era.

I've seen many a ROM be SuperMarioBros3.exe just straight up, but never .nes.exe so idk if that counts.

You're on linux? The odds of you getting a virus on linux are not 0 but very slim, since the userbase is very small.

Plus, viruses prey on people's ignorance. The usual "movie file viruses" are .exe files and can only be run on windows. Most people don't enable the option to show file extensions on windows, so a filed named "movie.mkv.exe" would show up as "movie.mkv" instead.

IMO, the odds of you accidentally running a virus by playing a .mkv file on linux are as high as the odds of you winning the lottery 3 times in a row.

Thanks for the reassurance. I won't worry about it. After some thought, I also believe it's unlikely some one have embed zero-day exploits into a movie torrent from LimeTorrent.

Yeah, zero-days are usually expensive because attackers like to keep them pre zero-days once they are discovered their value diminishes significantly. So they are usually used for high value targets and not on random people downloading movies.

if you really only played it and it didn't abuse some zero day in vlc (extremely unlikely), the there's basically zero chance you could have activated a virus.

But it's definitely possible to ship a virus embedded in a playable mkv file, but something else would have to extract it first, for it to do anything

Just make sure the file doesn't have a double extension. That can trick people into running a .exe when the file extension is hidden. That's really only a problem on windows though.

It’s possible to get a virus from any data that enters your computer full stop.

Likelyhood wise: that virus on the MKV will have to attack the operating system preview system (which means you fucked all the way up to personal nation state attention), or attack the video player (which is a lot more likelier, they discover theoretical exploits all the time).

You’re talking about streaming with VLC? Was it a trusted source? Cause otherwise the FBI or script kiddie has probably fucked you up.

Depends what you play it through TBH. If a program has access to your memory, then yes. Naturally it's a nuanced answer and unless you are a security expert that knows exactly how memory is allocated and how elevated privileges work, not to mention all the little bugs, etc. in your system, then the answer is yes. You aren't really safe from anything that hits your hard drive.