In 2017, we saw two large scale Ransomware attacks. The first began on May 12th, and was caused by a malware called “WannaCry”. The WannaCry attack affected over 230,000 computers in about 150 countries, including the National Health Service of the UK, forcing it to operate in a state of emergency. Just over one month later, on June 27th, another large scale attack occurred, with around 80% of affected machines in Ukraine. This attack is being called the “NotPetya” attack because it used a heavily modified version of ransomware from the Petya family of malware. It is believed to have originated from a compromised update of a Ukrainian tax accounting package called “MeDoc”. About 90% of firms in Ukraine use MeDoc, allowing the malware embedded in the update to travel quickly. Most notably affected was the radiation monitoring system at Ukraine's Chernobyl Nuclear Power Plant, causing to go offline. It also affected several Ukrainian ministries, banks, metro systems and state-owned enterprises.
What is Ransomware and how does it work?
Ransomware is a type of malware that works by infecting a Windows computer and encrypting the hard drive’s file system, making it impossible for the operating system to start up. In this state, the only thing the computer can do is prompt the user to pay a ransom, usually in an untraceable cryptocurrency such as Bitcoin. Once the ransom is paid, the attackers promise to decrypt the file system, returning the machine to a usable state. In the case of the WannaCry attack, users were advised not to pay the ransom of $300. Most who tried to pay were unable to when the Bitcoin wallet, setup for receiving the ransoms, was shut down. Luckily a sort of “kill switch” was built into the virus which slowed the spread.
In the case of NotPetya, instead of only encrypting data on the computer, important computer files were completely overwritten. The overwritten files could not be restored with decryption. This has lead experts to believe that the attack was only meant to look like a ransomware attack with the real intentions being to cause damage, not make a profit. Evidence suggests the attackers responsible for NotPetya compromised MeDoc’s servers more than a month before the attack leaving the server susceptible to additional attacks. NotPetya does not appear to have a “kill switch”.
How was it able to infect so many computers?
For WannaCry, Petya, and it’s modified version NotPetya, machines running the Microsoft Windows operating system were susceptible due to something called the EternalBlue exploit. The exploit takes advantage of a vulnerability in how Microsoft implements the SMB protocol (Windows network and file sharing protocol). On March 14th, 2017, Microsoft released a security announcement about the vulnerability and patches that were available for all supported versions of windows, nearly two months prior to the first attack. Many users had not installed the patches, leaving their PCs susceptible to the WannaCry. Microsoft also released emergency patches during the attack for some of their unsupported operating systems including Windows 7, Windows 8, Windows xp and Windows server 2003. The Verge stated that nearly all victims of WannaCry were running Windows 7.
According to security expert Lesley Carhart, "Every method of exploitation that the attack used to spread, was preventable by well-documented means," claiming the damage done in the attack could have been avoided with the available security patches. As more users and organizations applied security patches, and with the discovery of the “kill switch” the WannaCry attack slowed and had nearly been halted four days after the start of the attack. For the NotPetya attack, Ukraine announced that the attack was stopped only one day after it started. MeDoc’s compromised servers were seized in efforts to ensure no other attack would originate from them.
In order to keep your own machine safe from similar attacks, it is important to stay informed and up to date on cyber security news and events. It’s recommended to always apply any security updates as soon as they become available, and to use a quality security system.
Anna is a systems engineer at Hub City Media, with a focus in implementing access management solutions. She enjoys outdoor activities and spending time on the beach.
"Cyber-attack: Europol says it was unprecedented in scale". BBC. 13 May 2017
The WannaCry ransomware attack has spread to 150 countries". The Verge. 14 May 2017.
Kramer, Andrew. "Ukraine Cyberattack Was Meant to Paralyze, not Profit, Evidence Shows". The New York Times. 28 June 2017.
Borys, Christian "The day a mysterious cyber-attack crippled Ukraine". BBC. 28 June 2017.
Almost all WannaCry victims were running Windows 7". The Verge. Vox Media. 19 May 2017.