Common Types of Ransomware

Jan 24, 2018

Common Types of Ransomware

BY Chris Brunau

Ransomware

With the recent influx of ransomware stories seemingly every week, it's hard to keep track of the different strains. While each of these is spread in a different way, they generally rely on similar tactics to take advantage of users and hold data hostage. Let’s take a look at the common examples of ransomware:

  • Bad Rabbit: A strain of ransomware that has infected organizations in Russia and Eastern Europe.Bad Rabbit is spread through a fake Adobe Flash update on compromised websites. When the ransomware infects a machine, users are directed to a payment page demanding .05 bitcoin (about $285). 

  • Cerber: Cerber targets cloud-based Office 365 users and has impacted millions of users using an elaborate phishing campaign. This type of malware emphasizes the growing need for SaaS backup in addition to on-premises.

  • Crysis: This form of ransomware can encrypt files on fixed, removable, and network drives and it uses strong encryption algorithms and a scheme that makes it difficult to crack within a reasonable amount of time.

  • CryptoLocker: Ransomware has been around in some form or another for the past two decades, but it really came to prominence in 2013 with CryptoLocker. The original CryptoLocker botnet was shut down in May 2014, but not before the hackers behind it extorted nearly $3 million from victims. Since then, hackers have widely copied the CryptoLocker approach, although the variants in operation today are not directly linked to the original. The word CryptoLocker, much like Xerox and Kleenex in their respective worlds, has become almost synonymous with ransomware.

  • CryptoWall: CryptoWall gained notoriety after the downfall of the original CryptoLocker. It first appeared in early 2014, and variants have appeared with a variety of names, including CryptoBit, CryptoDefense, CryptoWall 2.0, and CryptoWall 3.0. Like CryptoLocker, CryptoWall is distributed via spam or exploit kits.

  • Crysis: Crysis ransomware encrypts files on fixed, removable, and network drives with a strong encryption algorithm making it difficult to crack in a reasonable amount of time. It is typically spread via emails containing attachments with double-file extension, which make the file appear as a non-executable file. In addition to emails, it can also be disguised as a legitimate installer for applications.

  • CTB-Locker: The criminals behind CTB-Locker take a different approach to malware distribution. Taking a page from the playbooks of Girl Scout Cookies and Mary Kay Cosmetics, these hackers outsource the infection process to partners in exchange for a cut of the profits. This is a proven strategy for achieving large volumes of malware infections at a faster rate.

  • GoldenEye: GoldenEye is similar to prolific Petya ransomware. Hackers spread GoldenEye ransomware through a massive campaign targeting human resources departments. After the file is downloaded, a macro is launched which encrypts files on the computer. For each file it encrypts, GoldenEye adds a random 8-character extension at the end. The ransomware then also modifies the user's hard drive MBR (Master Boot Record) with a custom boot loader. A

  • Jigsaw: Jigsaw encrypts and progressively deletes files until a ransom is paid. The ransomware deletes a single file after the first hour, then deletes more and more per hour until the 72-hour mark, when all remaining files are deleted.

  • KeRanger: According to ArsTechnica, KeRanger ransomware was discovered on a popular BitTorrent client. KeRanger isn't widely distributed, but it's known as the first fully functioning ransomware designed to lock Mac OS X applications.

  • LeChiffre: "Le Chiffre", which comes from the French noun "chiffrement" meaning "encryption", is the main villain from James Bond's Casino Royale novel who kidnaps Bond's love interest to lure him into a trap and steal his money. Unlike other variants, hackers must run LeChiffre manually on the compromised system. Cyber criminals automatically scan networks in search of poorly secured remote desktops, logging into them remotely and manually running an instance of the virus.

  • Locky: Locky's approach is similar to many other types of ransomware. The malware is spread in an email message disguised as an invoice. When opened, the invoice is scrambled and the victim is instructed to enable macros to read the document. When macros are enabled, Locky begins encrypting a large array of file types using AES encryption. 

  • NotPetyaInitial reports categorized NotPetya as a variant of Petya, a strain of ransomware first seen in 2016. However, researchers now believe NotPetya is instead a malware known as a wiper with a sole purpose of destroying data instead of obtaining a ransom. 

  • Petya: Unlike some other types of ransomware, Petya encrypts entire computer systems. Petya overwrites the master boot record, rendering the operating system unbootable. 

  • Spider: A form of ransomware spread via spam emails across Europe. Spider ransomware is hidden in Microsoft Word documents that install the malware on a victim’s computer when downloaded. The Word document, which is disguised as a debt collection notice, contains malicious macros. When these macros are executed, the ransomware begins to download and encrypt the victim's data.

  • TeslaCrypt: TeslaCrypt is another new type of ransomware on the scene. Like most of the other examples here, it uses an AES algorithm to encrypt files. It's typically distributed via the Angler exploit kit specifically attacking Adobe vulnerabilities. Once a vulnerability is exploited, TeslaCrypt installs itself in the Microsoft temp folder.

  • TorrentLocker: TorrentLocker is typically distributed through spam email campaigns and is geographically targeted with email messages delivered to specific regions. TorrentLocker is often referred to as CryptoLocker, and it uses an AES algorithm to encrypt file types. In addition to encoding files, it also collects email addresses from the victim’s address book to spread malware beyond the initially infected computer—this is unique to TorrentLocker.

  • WannaCry: WannaCry is a widespread ransomware campaign that is affecting organizations across the globe. The ransomware hit over 125,000 organizations in over 150 countries. The ransomware strain is also known as WCry or WanaCrypt0r and currently affects Windows machines through a Microsoft exploit known as EternalBlue.

  • ZCryptorZCryptor is a self-propagating malware strain that exhibits worm-like behavior, encrypting files and also infecting external drives and flash drives so it can be distributed to other computers.

While you don't exactly want to scare users when it comes to ransomware, it's important to be informed and understand how important it is to protect from ransomware. In our eBook: The Business Guide to Ransomware, we discuss the top ransomware threats to businesses today, how malware is spread, the best practices for protecting businesses, and more.

(This post is regularly updated with the latest strains of ransomware. Check back for more!)

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