I recently found and removed a trojan and infostealer from my computer using Malwarebytes. While cleaning up afterward, I noticed a folder named "Crypto" under my user profile's LocalLow directory. I mistakenly assumed it was related to the malware and deleted it, then learned it may be a legitimate Windows folder.
I immediately ran Windows File Recovery in regular mode and saved the recovered data to an external drive, but I cannot find the folder in the results. The computer has remained powered on, though I disconnected it from the internet and have avoided using other programs.
I'd like to know whether this folder is genuinely important, whether Windows can repair or recreate it, and whether a clean Windows installation would resolve both the malware concerns and any damage from deleting the folder. If recovery is necessary, should I stop using the computer and try an extensive scan or another recovery tool? If I locate the folder, would copying it back to its original location restore everything, or could deleting it have affected security keys, saved logins, or application data?
5 Answers
A repair installation or Windows system-file repair may recreate missing protected files, depending on which Crypto folder was deleted. It may not recreate user-specific keys, though. Applications that depended on those keys could lose stored login sessions and require you to sign in again. Before reinstalling, back up only personal documents, photos, and other files you trust—not programs or suspicious data.
A folder named Crypto under a Windows user profile is generally a legitimate system or application-related folder, not automatically malware. Its contents may include cryptographic keys used by Windows or individual applications. Simply copying back a recovered folder may not fully restore the original keys or fix every application, so don’t assume that will undo the deletion.
Stop using the computer for now. Any further activity can overwrite deleted data, especially if the drive is an SSD. Ideally, perform recovery from another computer or remove the drive and connect it to a separate system. The recovery destination should remain on a different drive, as you did with the external disk. Whether recovery is possible depends heavily on the drive type, how much it has been used since deletion, and the exact folder path.
If the computer previously had a trojan or infostealer, the safest approach is a clean Windows installation from trusted installation media. A reinstall will recreate Windows system files and provide a clean starting point, but it cannot restore deleted personal files or old encryption keys. Also change passwords from a known-clean device, enable multifactor authentication, and avoid restoring suspicious executables or unknown backups.
Windows File Recovery’s extensive mode can sometimes find more deleted files, but using the affected computer while deciding what to do reduces the chances of recovery. If the data is truly important, professional recovery is safer than repeatedly installing recovery tools. For a suspected malware infection, recovery should come second to securing accounts and rebuilding the system from clean media.
That makes sense. I was mainly worried that deleting the folder had permanently broken Windows, rather than just affecting a few applications.