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NotPetya ransomware attacks have spread to the U.S. Decryption may not be possible even if the ransom is paid. Details of how to prevent attacks are detailed below.
NotPetya Ransomware Attacks Spread to the United States
Tuesday’s global ransomware attack continues to cause problems for many organizations in Europe, with the attacks now having spread to North America. The spread of the ransomware has been slower in the United States than in Europe, although many organizations have been affected including at least three healthcare systems.
Pennsylvania’s Heritage Valley Health System has confirmed that its computer systems have been infected with the ransomware. The ransomware has affected the entire health system including both of its hospitals and its satellite and community facilities.
While medical services continue to be provided, computer systems were shut down and some non-urgent medical procedures were postponed. 14 of the health system’s community facilities were closed on Wednesday as a result of the attack and lab and diagnostic services were also affected
The health system’s communications director, Suzanne Sakson said, “Corrective measures supplied by our antivirus software vendor have been developed and are being implemented and tested within the health system.”
No evidence has been uncovered to suggest protected health information has been accessed, although an investigation into the incident is ongoing.
West Virginia’s Princeton Community Hospital has also been affected with many of the hospital’s computers taken out of action following infection with ransomware. An investigation has been launched to determine whether patient health information was potentially accessed. Hospital spokesperson Rick Hypes said the hospital has implemented its protocols for cyberattacks and patient care is continuing to be provided.
The New Jersey-based pharmaceutical firm Merck has also been affected.
While it was initially believed the attacks involved Petya ransomware, security researchers believe this is a Petya-like ransomware variant from the same family. It has already attracted a variety of names including NotPetya, SortaPetya, GoldenEye, Petna, Nyeta and ExPetr.
Decryption Unlikely, Even if the Ransom is Paid
The ransomware variant deletes and replaces the Master File Table (MFT) which prevents computers from being able to locate files. The attackers have collected some ransom payments, although recovering systems by paying the ransom may not be possible.
The attacker was using an email account through a German email provider; however, that email account has been suspended. The email account was used to verify payment of a ransom. Without access to that email account, payment verification would be prevented.
Security researchers at Kaspersky Lab have also discovered a flaw in the ransomware which prevents data recovery, even if the ransom is paid. Kaspersky Lab issued a statement saying “We have analyzed the high level code of the encryption routine and we have figured out that after disk encryption, the threat actor could not decrypt victims’ disks.”
Some security researchers have suggested that the goal of the attack was therefore not extortion but sabotage. Matt Suiche suggested in a recent analysis of the attack that “The ransomware was a lure for the media, this version of Petya actually wipes the first sectors of the disk like we have seen with malwares such as Shamoon.” However, also likely is a mistake by the attackers when developing their ransomware.
The number of victims has been steadily rising, with Kaspersky Lab identifying 2,000 attacks on Tuesday, while Microsoft now reports there has been at least 12,500 infections across 65 countries.
The attacks have hit multinational companies hard, with infections first occurring in European facilities but then subsequently spreading across networks to other geographical locations. Shipping firm Maersk had its Danish facilities infected, followed by infections in Ireland, the UK and other countries.
How to Prevent Infection with NotPetya Ransomware
Two exploits released by Shadow Brokers have been used to spread infections – EternalBlue and EternalRomance – both of which were addressed with the MS17-010 patch issued by Microsoft in March, which was subsequently expanded for use on non-supported Windows versions such as Windows XP following the WannaCry ransomware attacks last month.
However, if one computer on a network has not been patched the machine can be infected. The infection can then spread across a network to patched computers.
Even if all vulnerable machines have been patched, infection may still occur. The attackers are using multiple attack vectors including spam emails containing malicious attachments.
To protect against these NotPetya ransomware attacks – and other similar attacks – the MS17-010 patch must be applied to all Windows devices. Since data recovery may not be possible it is essential for data to be backed up, with multiple copies made, including one copy on an air-gapped machine that is not exposed via the Internet.
Rapid7 recommends organizations should “employ network and host-based firewalls to block TCP/445 traffic from untrusted systems.” Additionally, “if possible, block 445 inbound to all internet-facing Windows systems.”
PsExec and wmic.exe should also be disabled to limit the ability of the ransomware to spread.
Since infection can occur via email, organizations should send alerts to company employees alerting them to the risk of attack from infected email attachments, specifically – but not exclusively – Microsoft Excel spreadsheets.
Security researcher Amit Serper at Cyberreason suggests it is possible to ‘vaccinate’ computers to prevent encryption, with his method confirmed by a number of firms such as Emisoft and PT security.
Serper says, “Create a file called perfc in the C:\Windows folder and make it read only.” Details of how to do this are available on Beeping Computer.