JamieAug 28, 2023

WARNING: Lemmy Self-Hosters, There Have Been CSAM Attacks taking place against [email protected]

https://jamie.moe/post/113630

WARNING: Lemmy Self-Hosters, There Have Been CSAM Attacks taking place against [email protected] - Jamie Lemmy

There have been users spamming CSAM content in [email protected] [/c/[email protected]] causing it to federate to other instances. If your instance is subscribed to this community, you should take action to rectify it immediately. I recommend performing a hard delete via command line on the server. I deleted every image from the past 24 hours personally, using the following command: sudo find /srv/lemmy/example.com/volumes/pictrs/files -type f -ctime -1 -exec shred {} \; Note: Your local jurisdiction may impose a duty to report or other obligations. Check with these, but always prioritize ensuring that the content does not continue to be served. ## Update Apparently the Lemmy Shitpost community is shut down as of now.

Show threadmlfhAug 28, 2023

If you aren’t going to fully wipe your drive in horrible events like this, at the very least use shred instead of rm. rm simply removes references to the file in the filesystem, leaving the data behind on the disk until other data happens to be written there.

Do not ever allow data like that to exist on your machines. The law doesn’t care how it got there.

Show threadMic_Check_One_TwoAug 28, 2023

Was going to say the same. Windows and Linux both use “lazy” ways of deleting things, because there’s not usually a need to actually wipe the data. Overwriting the data takes a lot more time, and on an SSD it costs valuable write cycles. Instead, it simply marks the space as usable again, and removes any associations to the file that the OS had. But the data still exists on the drive, because it’s simply been marked as writeable again.

You need a form of secure delete, which doesn’t just mark the space is usable. A secure delete will overwrite the data with junk data. Essentially white noise 1’s and 0’s, so the data is completely gone instead of simply being marked as writeable.

Show threadlazynooblet
Would rm be okay if you regularly fstrim?
Aug 28, 2023 at 9:05amWeb
Show threadalanceilAug 28, 2023

No, fstrim just tells your drive it doesn’t need to care about existing data when writing over it. Depending on your drive, direct access to the flash chips might still reveal the original data.

If you want ensure data deletion, you’d need to zero out the whole drive and then fstrim to regain performance. Also see ATA Secure Erase.

Show threadAnaralah_Belore223Aug 28, 2023
Or physically destroy the whole drive altogether.
Show threadZacryonAug 29, 2023

TRIM tells the SSD to mark an LBA region as invalid and subsequent reads on the region will not return any meaningful data. For a very brief time, the data could still reside on the flash internally. However, after the TRIM command is issued and garbage collection has taken place, it is highly unlikely that even a forensic scientist would be able to recover the data.

From: en.m.wikipedia.org/wiki/Trim_(computing)#Operatio…

So: probably yes.

Trim (computing) - Wikipedia