Article
Ransomware Decryptors for a (varying) fee
Arete Analysis
Ransomware attacks wreak havoc on business operations. Destroying recovery options, instilling fear and panic, and most often creating high levels of stress for IT staff, owners, and operators. A simple, but often costly fix is to just pay the Threat Actor for the decryption utility. While making a payment to an anonymous entity is a highly debated topic, let us assume, for the purposes of this article, that the payment is the only option other than closing your business. Please note, Arete is not advocating to pay ransoms; the choice is entirely a business decision to pursue. This article is intended to provide insight into the various types of decryptors the threat groups provide to unlock your files. We will discuss specific decryptors for some of the more popular variants as well as address subtle nuances between the decryptors.
Full Disk Encryption
Ransomware variants like THT, Mamba, or MCrypt use native or opensource encryption software to encrypt the entire hard drive of the system. Once the TA gains access to the system with administrator privileges, the TA will use a tool like Bestcrypt, DiskCryptor or even Windows Bitlocker to encrypt the full disk. Once encryption is complete, the system reboots and the victims are locked out.
Communication preference: Email usually protonmail, firemail.cc, or cock.li domains
Average ransom payment: $36,000 – $55,000
Preferred currency: Bitcoin (BTC)
Decryptor received: 100% of the time. TA will provide passwords per system for access
Watch out: MCrypt will hold volumes hostage and “re-extort” victims into making multiple payments. During the initial negotiation, the TA will not indicate multiple drives are encrypted. Instead they will negotiate a single amount for initial access to the Operating System; essentially allowing access into Windows. Once access to Windows is regained, victims often surprised to find their “data” partitions are encrypted causing the victim to return to the negotiation table to once again shell out more money to unlock their information.
Notes: After gaining access, the open source encryption tool still needs to be removed otherwise after reboot, the data storage will be locked again.
System Specific Encryption
Ransomware variants like Phobos, Dharma or CryLock are file level encryption. The TA gains access to the system, copies specific encryption executables onto the systems then runs the executables to encrypt the files. The results are files with a new extension appended to the old file name. Sometimes it’s a random sequence of numbers and letters (e.g. *.nocv) or a specific tag (e.g. *[CryLockDecrypt@****.com][1].[ID-*****- COM]). System specific encryption generates a unique key per encrypted system. The ransom note or the file extension may indicate an “ID” that would be different on each system.
CryLock Scanner & Decryptor
Communication preference: Email usually aol.com, protonmail.com, or cock.li domains
Average ransom payment: $27,000 – $500,000
Preferred currency: Bitcoin (BTC)
Decryptor Received: 95% of the time. Certain variants of Phobos and Dharma will attempt to re-extort a second payment if a large discount is negotiated.
Watch out: Phobos, Dharma, and CryLock are a two-step process. The TA will first send a “scanner” tool that needs to be run on every infected system. The scanner will look for the public keys used to encrypt the files, then write that information to a corresponding .txt or .ini file. Those corresponding files need to be sent to the TA in order to generate a decryptor. The TA in return will send the decryptors. The two-step process adds significant overhead due to the running of multiple tools on the infected system as well as the delay with communicating via email. On average after making a payment for the decryptor, clients are who are infected with Phobos are down for approximately 11 days whereas clients who are infected with Dharma experience downtime of about 7.75 days. The high number of days can be attributed to the two-step process and multiple email communications.
Notes: Negotiating with the Phobos and Dharma group can be tricky. These variants are Ransom-as-a-Service (RaaS) model so you’re not dealing with the same core group of people as you would with variants like Ryuk (or now Conti). Negotiating with RaaS groups can also create confusion and complexities with a different operator responding to each email. The groups who deploy these variants also look for exploiting publicly accessible Remote Desktop Protocol (RDP). Disable external access to RDP to lessen the chance of being infected by this variant.
System Specific Encryption with a Universal Option
Ransomware variants like Sodinokibi are file level encryption with a unique ID per system. Once the TA gains access to the network, they release their Sodinokibi ransomware throughout the environment. The systems are infected with a unique randomly generated file extension per system. Their ransom notes are usually within a text file and explain what happened, including if any data was exfiltrated. The group is very organized and can often share information about their victim’s networks including domain information, infected systems, and any stolen data.
Sodinokibi Decryptor
Communication preference: TOR Website via chat room. The ransom note contains a link to the TOR site as well as a unique key to gain access to a private chat room where the negotiations occur.
Average ransom payment: $170,000
Preferred currency: Monero (XMR)
Decryptor received: 100% of the time. Sodin offers a general decryptor which requires the victim to collect the file extensions from all of their infected systems. This can be very tedious once the payment is made, the victim can input any number of file extensions into the input box on the TOR site to generate a decryptor. Sodin will keep that private room open for 30 days after payment allowing victims to return if they find any extensions not previously found. A lesser known secret with Sodin, if you ask nicely for a universal decryptor, the operator may create the decryptor for you; providing a single decryptor that can be used across your network. The universal decryptor certainly saves a lot of time with decrypting files and minimizing the number of times having to launch the TOR browser.
Watch out: Earlier this year, Sodin changed their code base for their encryption payloads causing instability on certain Windows Operating Systems within the master boot files. Using certain security tools after a Sodin outbreak can cause systems to hang during reboot. Sodin encryption is one of the more aggressive encryptions.
Be sure to create a snapshot or backup the files prior to installing any new software or performing live forensics on critical systems.
Notes: Sodin has made headlines throughout 2020 for following Maze with exfiltrating data as well as being the first ransomware group to only accept Monero for payments.
System Specific Encryption with a Universal Option
Ransomware variants like Sodinokibi are file level encryption with a unique ID per system. Once the TA gains access to the network, they release their Sodinokibi ransomware throughout the environment. The systems are infected with a unique randomly generated file extension per system. Their ransom notes are usually within a text file and explain what happened, including if any data was exfiltrated. The group is very organized and can often share information about their victim’s networks including domain information, infected systems, and any stolen data.
Sodinokibi Decryptor
Communication preference: TOR Website via chat room. The ransom note contains a link to the TOR site as well as a unique key to gain access to a private chat room where the negotiations occur.
Average ransom payment: $170,000
Preferred currency: Monero (XMR)
Decryptor received: 100% of the time. Sodin offers a general decryptor which requires the victim to collect the file extensions from all of their infected systems. This can be very tedious once the payment is made, the victim can input any number of file extensions into the input box on the TOR site to generate a decryptor. Sodin will keep that private room open for 30 days after payment allowing victims to return if they find any extensions not previously found. A lesser known secret with Sodin, if you ask nicely for a universal decryptor, the operator may create the decryptor for you; providing a single decryptor that can be used across your network. The universal decryptor certainly saves a lot of time with decrypting files and minimizing the number of times having to launch the TOR browser.
Watch out: Earlier this year, Sodin changed their code base for their encryption payloads causing instability on certain Windows Operating Systems within the master boot files. Using certain security tools after a Sodin outbreak can cause systems to hang during reboot. Sodin encryption is one of the more aggressive encryptions.
Be sure to create a snapshot or backup the files prior to installing any new software or performing live forensics on critical systems.
Notes: Sodin has made headlines throughout 2020 for following Maze with exfiltrating data as well as being the first ransomware group to only accept Monero for payments. eir.co
Universal Encryption
Ransomware variants like Ryuk, WastedLocker, and Dopplepaymer are also file level encryption. These groups will gain access to the network and perform reconnaissance to identify the victim, understand their business, identify critical systems, and delete backups to force their victims into making a payment. The groups can have access to the network for a few hours or upwards of over a month. Ryuk is commonly associated with precursor trojans such as Trickbot and Emotet. Arete has observed Ryuk deployed as quickly as 6 hours after a Trickbot infection. Ryuk infections result with *.ryk appended to the file name. Comparatively, the deployment of WastedLocker is much more calculated with the TA staying on the network for an average of 2 weeks from initial infection to ransomware deployment. Wasted infections result with *.abcwasted appended to the file name where “abc” is a 3 letter abbreviation relating directly to the victims name.
WastedLocker Decryptor
Communication preference: Email usually protonmail.com domains or TOR Website
Average ransom payment: Ryuk $598,000; WastedLocker $2,400,000; Dopplepaymer $304,000
Preferred currency: Bitcoin (BTC)
Decryptor received: 100% of the time. The decryptor received is universal. It is typically a 32-bit executable that will work on any windows OS version. While these groups are known for a high ransom price, their decryptor is probably the simplest to run.
Watch out: WastedLocker is extremely difficult to negotiate. In fact, if negotiation is attempted, they may threaten to increase the ransom by approximately 5% of the ransom per day until it is paid. They are also very slow to respond to email and even post their business hours of UTC 5am- 8am and 5pm-8pm.
Notes: Dopplepaymer has been linked to gaining access to large environments and deploying cryptomining malware before launching their ransomware attack.
Pro Tips to Prevent Ransomware
Attacks
Implement Endpoint, Detection, and Response software such as SentinelOne to monitor the computer systems in use by your organization. SentinelOne uses Artificial Intelligence technology to detect malicious actions and prevent them before they can severely affect the endpoint.
Leverage a Security Operations Center (“SOC”) to monitor computer systems 24 hours a day by 7 days a week. The SOC can instantly respond to triage and mitigate any alerts while keeping your IT personnel focused on maintain business productivity.
Enable Multi-Factor Authentication (“MFA”) on remote access technologies such as VPN and Email.
Use complex passwords with a minimum of 16 alphanumeric characters (non- dictionary words).
Don’t reuse passwords.
Encourage discussion about cybersecurity within the workplace including establishing end user awareness training.
Ensure backups are current, air gapped from the production network, and viable.
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Article
Phishing-as-a-Service Evolves with Venom
“Whaling” has taken on a new meaning with a highly targeted phishing campaign active from November 2025 through March 2026, aimed exclusively at senior executives from more than 20 industries. The campaign, dubbed VENOM, is a phishing-as-a-service (PhaaS) platform that combines advanced evasion capabilities with immediate persistence of targeted executives. The initial phish impersonates an internal SharePoint document notification and uses embedded QR codes to convince victims to shift to unmanaged mobile devices to bypass corporate security controls. VENOM aims to establish persistence immediately by either registering a new MFA device or retaining long-lived refresh tokens, allowing threat actors to maintain access even after password resets or other base-level remediation efforts.
What’s Notable and Unique
This campaign is unique in its targeted nature of the PhaaS platform rather than broad, sweeping attempts. The threat actors behind VENOM create convincing phishing emails that impersonate SharePoint activity using the victim’s own domain, company name, and even fabricated email threads. These convincing social engineering tactics, combined with the specific targeting of executives, make this an effective capability for cybercriminals.
VENOM operates as a closed-access system, with full adversarial support, but has no public visibility on the dark web or from security researchers. The service likely operates on an invite-only basis, unlike most PhaaS platforms, which typically seek to have as many paying customers as possible. This, among other items such as the sophisticated evasion techniques, indicates a higher degree of sophistication than most other PhaaS offerings.
Either through MFA enrollment or Microsoft Device Code abuse, the threat actor forces the victim to aid them in establishing persistence early in the attack lifecycle. These tactics result in either valid tokens or an additional MFA login method controlled by the threat actor, meaning typical password resets alone are not effective against this technique. Administrators would be required to explicitly revoke sessions and token grants to mitigate the threat actors’ persistence.
Analyst Comments
Oftentimes, MFA is viewed as a one-stop shop to cybersecurity, but tactics such as this show how threat actors can bypass MFA, or worse, use it to establish persistence. Ultimately, this campaign highlights how modern attacks increasingly abuse legitimate authentication workflows rather than attempting to defeat them outright. Defenses that rely solely on MFA without other security posturing, such as continuous session monitoring, token revocation, and identity logging, can leave organizations vulnerable. As attackers shift toward token theft and device trust abuse, incident response and identity security strategies must evolve accordingly.
Sources
Meet VENOM: The PhaaS Platform That Neutralizes MFA
Article
Threat Actors Continue to Leverage BYOVD Technique
Multiple ransomware operations have recently been observed leveraging the Bring Your Own Vulnerable Driver (BYOVD) technique to disable endpoint security controls prior to ransomware deployment. Notably, the Qilin ransomware group commonly leverages a malicious msimg32.dll file loaded via DLL side-loading, along with vulnerable drivers including rwdrv.sys and hlpdrv.sys, to gain kernel-level access and disable security processes. Similarly, Warlock ransomware has been observed exploiting the vulnerable NSecKrnl.sys driver to bypass security controls. The use of BYOVD has also been observed across ransomware campaigns associated with Akira, INC, Medusa, and other threat actors.
What’s Notable and Unique
The Qilin ransomware group employs a sophisticated multi-stage infection chain, leveraging DLL side-loading (msimg32.dll) to execute malicious payloads directly in memory and evade traditional file-based detection. In DLL side-loading, a threat actor tricks a program into loading a malicious dynamic link library. The malware escalates privileges and uses signed but vulnerable drivers (rwdrv.sys and hlpdrv.sys) to bypass security controls, access system memory, and systematically disable endpoint defenses by terminating security processes and disabling monitoring callbacks at the kernel level.
Akira ransomware operators have also exploited the rwdrv.sys and hlpdrv.sys drivers. Additionally, Arete has observed threat actors leveraging multiple other drivers, including the vulnerable TrueSight.sys, to bypass security controls.
Meanwhile, Warlock ransomware operators disguised malicious activity by renaming rclone.exe to TrendSecurity.exe to appear legitimate. The file functioned as a loader, exploiting the vulnerable NSecKrnl.sys driver to disable security processes, while Group Policy Objects (GPOs) were leveraged to systematically disable security controls across the environment.
Analyst Comments
The BYOVD technique, employed by multiple known ransomware operators, reflects a broader shift toward pre-encryption defense evasion, including suppression of Windows telemetry, removal of monitoring callbacks, and abuse of legitimately signed but vulnerable drivers. This technique enables threat actors to evade detection, maintain persistence for extended periods, and maximize the operational impact of ransomware deployment across compromised environments. Organizations should implement strict driver control policies, such as Microsoft’s Vulnerable Driver Blocklist and application control mechanisms. Additionally, enforcing least privilege access, enabling multi-factor authentication (MFA), maintaining up-to-date patching, and continuously monitoring for anomalous driver and kernel-level activity can further reduce the risk of such attacks.
Sources
Qilin EDR killer infection chain
Web Shells, Tunnels, and Ransomware: Dissecting a Warlock Attack
Article
Ransomware Trends & Data Insights: March 2026
The threat landscape in March had a much more even distribution of threat groups than has been observed since the first half of 2025. Although Akira, Qilin, Play, and INC remained among the most active groups, Arete observed 21 unique ransomware and extortion groups in March, compared to only 15 in February. Akira and Qilin’s activity also declined from the previous month; in February, the two groups were responsible for almost half of all ransomware incidents, but in March they only comprised a little more than a quarter of all activity. Arete also observed activity from several emerging groups in the past month, including BravoX, NightSpire, Payouts King, and Securotrop.
Figure 1. Activity from the top 5 threat groups in March 2026
Analysts at Arete identified several trends behind the threat actors perpetrating cybercrime activities:
In March, threat actors actively exploited FortiGate Next-Generation Firewall appliances as initial access vectors to compromise enterprise networks. The activity involves the exploitation of recently disclosed security vulnerabilities, including CVE-2025-59718, CVE-2025-59719, and CVE-2026-24858, or weak credentials, allowing attackers to gain administrative access, extract configuration files, and obtain service account credentials. Arete also observed Fortinet device exploitation involving various threat groups, with the Qilin ransomware group notably leveraging Fortinet device exploits.
Phishing campaigns leveraging OAuth redirection and a resurgence of Microsoft Teams–based social engineering were also observed in March. In one campaign, attackers sent emails disguised as Microsoft Teams recordings or Microsoft 365 alerts, redirecting victims through legitimate OAuth endpoints to attacker-controlled pages hosting malicious ZIP payloads. A separate campaign has been ongoing since last year, in which attackers flood users’ inboxes with spam and impersonate IT support personnel to trick victims into initiating remote support sessions via tools like Quick Assist.
Arete recently released its 2025 Annual Crimeware Report. Leveraging data and intelligence collected during ransomware and extortion incident response engagements, this report highlights notable trends and shifts in the threat landscape throughout 2025, including Akira’s unusually high activity levels in the second half of 2025, evolving social engineering techniques, and trends in ransom demands and impacted industries.
Sources
Arete Internal
Report
Arete's 2025 Annual Crimeware Report
Harness Arete’s unique data and expertise on extortion and ransomware to inform your response to the evolving threat landscape.