Connect with us

Hi, what are you looking for?



Encryptor RaaS Shuts Down Without Releasing Master Key

Security researchers earlier this year managed to zero-in on the Encryptor Ransomware-as-a-Service (Raas), which forced the developer to shut down the operation, but without releasing the master key to help victims.

Security researchers earlier this year managed to zero-in on the Encryptor Ransomware-as-a-Service (Raas), which forced the developer to shut down the operation, but without releasing the master key to help victims.

The ransomware service first emerged in July 2015 as a multiplatform threat at an appealing price, and managed to become a considerable threat to users and businesses fast, Trend Micro researchers reveal. Attacks leveraging this piece of ransomware could be easily tailored by affiliates, and Encryptor RaaS author created a full web panel for his patrons, which could be accessed only via the Tor network.

The same as with other ransomware, Bitcoin was the preferred transaction currency, and the earnings looked highly appealing for affiliates, as they had to share only 5% of their revenue to the author. Other similar services out there, such as Cerber, would require affiliates to pay 40% in commissions, Trend Micro explains (the Cerber campaigns generate an estimated $2.3 million in annual revenue). 

Encryptor RaaS was being advertised in surface web and darknet forums and interested parties only needed to contact the developer to show interest. Technical expertise wasn’t a requirement, though affiliates needed to know how to set up a Bitcoin Wallet ID, which would be attached to the distributed ransomware variant. Affiliates were also provided with a “customer ID” and could choose the ransom amount and the distribution method.

The malware was written purely in C language, used a combination of RC6 and RSA-2048 algorithms to encrypt 231 file types, generated an ID for each victim, and had its entire infrastructure hidden within the Tor network. Victims were instructed to use Tor2Web or the Tor Browser to access the payment site and could also use a chat box to contact the cybercriminals.

The ransomware’s author focused on avoiding detection and even started offering a file-signing service for affiliates, saying that he had access to stolen Authenticodes. Encryptor RaaS was improved to become virtually undetectable, being able to trick static engine analysis, but still being caught by behavioral detection.

While analyzing the threat, researchers discovered that the actor left a command and control (C&C) server either abandoned or mistakenly open: it was exposed and not anonymized by Tor. Thus, researchers determined that Encryptor RaaS was being hosted on a legitimate cloud service, and one of the RaaS’s systems was seized in June.

Advertisement. Scroll to continue reading.

The operator immediately took the infrastructure down as a precautionary measure, but more servers were seized a few days later. However, the developer managed to bring the entire system back online after four days, and also announced that it would shut down the operation. A shutdown notice was posted on all the main pages of decryptor sites, and Encryptor RaaS’s main site.

“Encryptor RaaS’s systems went down around 5 PM GMT on July 5, 2016, with the developer leaving victims a message that they can no longer recover their files, as he deleted the master key,” Trend Micro reveals. Thus, while there’s one less ransomware family to worry about, there are users left without the possibility of recovering their files.

Related: Locky Ransomware Drops Offline Mode

Related: New MarsJoke Ransomware Targets Government Agencies

Written By

Ionut Arghire is an international correspondent for SecurityWeek.

Click to comment

Daily Briefing Newsletter

Subscribe to the SecurityWeek Email Briefing to stay informed on the latest threats, trends, and technology, along with insightful columns from industry experts.

Join security experts as they discuss ZTNA’s untapped potential to both reduce cyber risk and empower the business.


Join Microsoft and Finite State for a webinar that will introduce a new strategy for securing the software supply chain.


Expert Insights

Related Content


The changing nature of what we still generally call ransomware will continue through 2023, driven by three primary conditions.


As it evolves, web3 will contain and increase all the security issues of web2 – and perhaps add a few more.


A recently disclosed vBulletin vulnerability, which had a zero-day status for roughly two days last week, was exploited in a hacker attack targeting the...


Luxury retailer Neiman Marcus Group informed some customers last week that their online accounts had been breached by hackers.


Zendesk is informing customers about a data breach that started with an SMS phishing campaign targeting the company’s employees.


Satellite TV giant Dish Network confirmed that a recent outage was the result of a cyberattack and admitted that data was stolen.

Artificial Intelligence

The release of OpenAI’s ChatGPT in late 2022 has demonstrated the potential of AI for both good and bad.


A new study by McAfee and the Center for Strategic and International Studies (CSIS) named a staggering figure as the true annual cost of...