pwshub.com

Ransomware victim paid hacker, but decryption failed

Serving tech enthusiasts for over 25 years.
TechSpot means tech analysis and advice you can trust.

Bottom line: Victims of ransomware attacks are typically advised not to pay the ransom demanded by cybercriminals. Paying up offers no guarantee that the attackers will uphold their end of the deal, like providing access to encrypted files.

GuidePoint Security recently acted as a "negotiator" between an unnamed company and the group behind the Hazard ransomware. The malware infected the victim's systems, encrypting "important" files and demanding payment to unlock them. The company reportedly felt compelled to pay, but the "decryptor" provided by the Hazard creators didn't work as expected.

While dealing with unreliable decryptors isn't common, GuidePoint explained, things in the malware world can sometimes behave unpredictably. After negotiating with the cybercriminals, the researchers were tasked with investigating why the newly acquired decryption tool was unable to restore the encrypted files.

The root cause was a bug in the encryption payload used by the Hazard ransomware. "A race-condition occurred when the threat actor executed multiple encryptors on the same system," GuidePoint determined. Each file was encrypted a second time before being renamed with a new extension, resulting in missing bytes within a chunk of data appended to the original file.

The appended data was required to recover the encryption initialization vector (IV), but the last three bytes were missing after encryption. Since the IV was pseudo-randomly generated by the encryption payload, retrieving the missing bytes initially seemed impossible.

The ransomware creators were likely unaware of this bug in their malware. After identifying why the decryptor wasn't functioning, GuidePoint attempted to escalate the issue with the Hazard "technical support" team. However, the threat actors merely provided the same decrypting tool under a different name before disappearing.

As the encrypted files were valuable, GuidePoint was tasked with developing a working solution. The researchers succeeded by adopting a brute-force approach, testing all possible combinations for the missing bytes in the IV, ultimately recovering the clean files.

Costs associated with ransomware incidents are on the rise, and even "zombie" malware operations like LockBit 3.0 continue to claim victims. After dealing with a faulty decryption tool, GuidePoint emphasized that ransom payments should never be made. Adopting best practices for data backups is crucial, and even backing up encrypted data can be helpful in unique situations like the recently disclosed Hazard incident.

Source: techspot.com

Related stories
1 hour ago - Boasts 'appear to be credible' experts tell El Reg A California city, a Spanish fashion giant, an Indian paper manufacturer, and two pharmaceutical companies are the alleged victims of what looks like a new ransomware gang that started...
1 month ago - Authorities allege 'J.P. Morgan' practiced ‘extreme operational and online security’ The US has charged a suspect they claim is a Belarusian-Ukrainian cybercriminal whose offenses date back to 2011.…
1 week ago - Would paying a ransom - or better security - have been cheaper and safer? A US healthcare giant will pay out $65 million to settle a class-action lawsuit brought by its own patients after ransomware crooks stole their data – including...
1 month ago - Plus many more newbies waiting in the wings Despite a law enforcement takedown six months ago, LockBit 3.0 remains the most prolific encryption and extortion gang, at least so far, this year, according to Palo Alto Networks' Unit 42.…
1 week ago - No class: Black Suit ransomware gang boasts of 200GB haul from one raid Cybercriminals closed some schools in America and Britain this week, preventing kindergarteners in Washington state from attending their first-ever school day and...
Other stories
16 minutes ago - Write better code, urges Jen Easterly. And while you're at it, give crime gangs horrible names like 'Evil Ferret' Software developers who ship buggy, insecure code are the real villains in the cyber crime story, according to Jen Easterly,...
55 minutes ago - The Indian government has approved $2.7 billion in new spending for its space program.
55 minutes ago - heard you like apps — Windows App replaces Microsoft Remote Desktop on macOS, iOS, and Android. Enlarge / The...
55 minutes ago - LinkedIn limits opt-outs to future training, warns AI models may spout personal data.
55 minutes ago - BUSTED — iServer provided a simple service for phishing credentials to unlock phones. Getty Images ...