#Ransomware on mac computers install#
#Ransomware on mac computers software#
#Ransomware on mac computers code#
#Ransomware on mac computers password#
#Ransomware on mac computers download#

Make regular backups and keep a recent backup copy offline, and preferably also offsite.

#Ransomware on mac computers download#

Consider running a Mac anti-virus that can automatically scan the files you download before you run them for the first time, and that can check out the websites you try to access before your browser gets to them.

#Ransomware on mac computers password#

(Some Mac users still wrongly think that a password dialog is an inevitable side-effect of a malware infection, and is thus a handy way to spot that something malicious is about to happen вЂ“ but thatвЂ™s not correct.) What to do? That means you wonвЂ™t see any dialogs popping up asking for your administrative password. Note that the ransomware program doesnвЂ™t try to acquire administrative powers, because it doesnвЂ™t need them to access your files: if you can write to them, so can any malware that you launch by mistake. The General.rtf file is, in fact, a regular OS X executable file, and it is launched under the innocent-looking name kernel_service by the hacked Transmission app.ДЄfter waiting for 259,200 seconds (72 hours, or three days), the ransomware triggers and the damage listed above is carried out.

#Ransomware on mac computers code#

The Transmission app itself was very slightly modified to include an additional snippet of code to run the malware, which was added to the Transmission package under the innocent-looking name General.rtf. The crooks hacked into the download server of a popular BitTorrent client called Transmission, created a fake version numbered 2.90, and published it as an official download on the site. This one has been distributed differently вЂ“ so far, at any rate. DOC files) that are attached to the email. Most Windows ransomware in recent months arrives via email, embedded in Word documents (. The idea of the вЂњdecrypt one freeвЂќ feature, now commonplace in Windows ransomware, is to try to convince you that the crooks really do have the decryption key for your files, or else they wouldnвЂ™t be able to unscramble a file randomly chosen by you. There are even вЂњdecrypt one freeвЂќ and вЂњask us a questionвЂќ options, too: ThereвЂ™s a Frequently Asked Questions page: (ItвЂ™s easy to be high and mighty when itвЂ™s not your data on the line!) We recommend that you donвЂ™t pay, but if you do, we understand and respect your choice. We havenвЂ™t paid up to see what happens, so we canвЂ™t tell you whether we think youвЂ™d receive an unscrambling key if you were to pay.

#Ransomware on mac computers software#

If you login with your personal authentication ID, youвЂ™ll get to the main pay page, where you can see how much youвЂ™ve deposited so far once youвЂ™ve paid up, the button will light up, and you can fetch the software and the decryption key you need to get your files back: onion address, a website visible only inside Tor, better known as the hidden web or the dark web: If you donвЂ™t have a backup from which you can restore your scrambled files, the only practical way to get them back, as far as we can see, is to follow the instructions in the README_FOR_DECRYPT.txt file: The random AES keys are then encrypted with an RSA public key downloaded from the crooks the crooks keep the corresponding RSA private key to themselves, so they end up with the master key to all your files.

In fact, because your files have been strongly encrypted with random keys using the AES algorithm, they are indistinguishable from random garbage. encryptedfiles, youвЂ™ll be confronted with random-looking binary garbage. The malware will scramble everything in can find in your home directory (that means in and below /Users/YourNameHere), and a long list of file types on all mounted volumes such as USB keys, removable disks and network shares (on OS X, thatвЂ™s everything under /Volumes).

Put a file called README_FOR_DECRYPT.txt in every directory where a file was encrypted.

Scramble files in your home directory and on currently-mounted volumes, adding the extension.

Call home to one of a list of control servers for an encryption key.

#Ransomware on mac computers install#

When you do so, install and run the ransomware program.

Trick you into opening a file you are inclined to trust.

HereвЂ™s what the crooks and their malware do: The crooks have largely copied the ransomware formula that works on Windows. (And, no, if you are a Windows user you are not allowed to be smug, because an injury to one operating system is an injury to all.) ItвЂ™s happened: thereвЂ™s now ransomware for the Mac, and itвЂ™s called OSX/KeRanger-A.

Thanks to Anna Szalay and Xinran Wu of SophosLabs for their behind-the-scenes work on this article.