Ransomware Decryptors for a (varying) fee

Article

Ransomware Decryptors for a (varying) fee

Dec 24, 2020

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

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)

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

Nov 9, 2026

Ransomware Trends & Data Insights: October 2026

Although Akira once again emerged as the most active ransomware group in October, overall ransomware and extortion activity was not dominated by any single threat group and instead remained widely distributed among a variety of threat actors, continuing the trend that began around August. Arete identified 31 unique named threat groups in October, the most observed in a single month so far in 2026. In addition to Akira, Settra, and The Gentlemen were among the three most active groups. Several new threat actors also emerged, including BYOD, Kubera Team, QWCrypt, AoQin, Emperador, Osiris Team, and Cinder, with Cinder assessed as possibly part of a threat actor cluster affiliated with the former BlackFile group.

Figure 1. Activity from the top 10 threat groups in October 2026

Throughout the month, analysts at Arete identified several trends behind the threat actors perpetrating cybercrime activities:

PHP2Shell emerged as one of the most significant threats in October, with increasing exploitation of the critical PHP vulnerabilities CVE-2026-109618 and CVE-2026-109619. Other notable vulnerabilities included CVE-2026-104286 affecting FortiMail, and CVE-2026-102255, a critical pre-authentication Server-Side Request Forgery (SSRF) vulnerability affecting SonicWall SMA1000 appliances, highlighting continued threat actor interest in internet-facing enterprise infrastructure.

International law enforcement operations against cybercriminal groups continued to make headlines in October. German authorities announced the arrest of 28-year-old Russian national Vladimir K., suspected of being a senior operator within the Qilin Ransomware-as-a-Service (RaaS) group. Separately, the FBI arrested an individual with suspected links to ShinyHunters, adding to recent law enforcement activity targeting ransomware and extortion groups, including the disruption of KillSec. While Vladimir K.’s arrest has not yet had a notable impact on Qilin’s operational activity, it could provide law enforcement with greater insight into the group’s infrastructure and affiliate network, potentially supporting further disruption efforts.

In early October, “The Luna Moth Files” exposed several files containing alleged internal communications associated with Luna Moth, also known as Silent Ransom Group, revealing insights into the group’s social engineering, data extortion, and victim negotiation operations. However, several claims remain unverified, and the exposure has not notably disrupted the group’s activity thus far, as it was among the top threat actors Arete observed throughout the month.

Sources

Arete Internal

Article

Nov 2, 2026

PHP2Shell Exploitation Update

PHP2Shell exploitation activity continues to increase globally, with threat actors targeting the critical PHP remote code execution (RCE) vulnerabilities CVE-2026-109618 and CVE-2026-109619. Researchers recently identified low-volume scanning targeting unpatched or partially mitigated hosts across multiple countries and sectors, and the activity is assessed with moderate confidence as linked to a Korean-speaking operator associated with the Lazarus Group ecosystem. While PHP2Shell (CVE-2026-109618 and CVE-2026-109619) has been patched in PHP 8.5.12, 8.4.27, 8.3.36, and 8.2.35, the separately identified CVE-2026-115560 remains unpatched.

What’s Notable and Unique

PHP2Shell vulnerabilities can cause memory corruption due to improper error handling, potentially allowing threat actors to achieve remote code execution on vulnerable PHP servers.
Observed activity includes mass scanning, PHP environment fingerprinting, exploitation attempts, credential and secret theft attempts, and attempts to deliver second-stage payloads and malware.
Successful in-the-wild exploitation has also been reported against honeypots, resulting in shell command execution and the retrieval of additional payloads, demonstrating the potential for follow-on malicious activity.

Mitigations

Organizations should prioritize upgrading internet-facing PHP deployments to patched versions, migrating unsupported PHP versions, updating embedded and containerized PHP runtimes, and implementing available Web Application Firewall (WAF) protections as a temporary defense-in-depth measure.

Analyst Comments

PHP2Shell poses a significant security concern due to its potential to enable unauthenticated remote code execution on vulnerable PHP servers. The progression from mass scanning and exploitation attempts to reports of successful command execution demonstrates the potential for these vulnerabilities to support initial access and subsequent malicious activity. Arete has been closely monitoring PHP2Shell exploitation activity and regularly reviewing and updating related indicators to support detection and blocking efforts. Given the potential for remote exploitation and follow-on activity, PHP2Shell represents a high-priority initial-access risk, emphasizing the importance of timely patching and remediation of affected PHP environments.

Sources

PHP shares mitigation for new RCE vulnerability with no patch
PHP2Shell Exploitation Attempts Continue Amid Suspected N. Korea Global Scanning Activity
PHP2Shell Exploit Attempts Hit Millions as Attackers Try to Deploy Mirai Malware
Advisory: PHP2Shell Vulnerabilities (CVE-2026-109618, CVE-2026-109619)

Article

Oct 30, 2026

LiteLLM Supply-Chain Compromise

A software supply-chain attack compromised the release pipeline of LiteLLM, a widely used open-source Python SDK and AI gateway. Attackers leveraged the compromised pipeline on October 21st to publish a malicious LiteLLM version through PyPI and associated Docker registries. The affected release, LiteLLM 1.107.0, contained malware designed to steal credentials, sensitive configuration data, private keys, browser information, and other secrets from compromised systems.

What’s Notable and Unique

The incident is particularly significant because LiteLLM provides a common API for applications to interact with AI models from multiple providers. It is reported that the project had approximately 61,800 GitHub stars and 92 million monthly PyPI downloads.
Rather than modifying the core LiteLLM application source code, the threat actors reportedly tampered with the installation package itself. The malware was designed for broad credential and information theft and encrypted the collected data before uploading it to the attacker's endpoint.
The compromise went beyond one-time credential theft. A malicious Python component launched a detached loader that checked a GitHub-hosted pointer every hour and could download Python code from an external server for execution on the compromised machine. This provided threat actors with a mechanism for subsequent remote code execution.

Analyst Comments

Although the malicious packages were subsequently removed, simply uninstalling or deleting the affected LiteLLM package may not be sufficient, because malicious Python startup files or the detached loader could remain on the host. All exposed information should be rotated immediately, and infected systems should be isolated and rebuilt from clean backups. The most recent clean release prior to the attack, LiteLLM 1.106.2, is currently the suggested recovery version.

Sources

LiteLLM release pipeline hacked to distribute info-stealer malware
LiteLLM 1.107.0 Compromised: Python Startup Hooks Steal Cloud, AI, and Proxy Credentials
The Collector Reaches Beyond Provider API Keys

Article

Oct 27, 2026

French Supermarket Cyberattack Highlights Risks in Exposed Refrigeration Controllers

Hundreds of French supermarkets were reportedly affected by a cyberattack in which threat actors compromised internet-connected refrigeration controllers and manipulated temperature and defrost settings, which caused refrigeration units to overheat, resulting in widespread food spoilage and significant financial loss. Impacted refrigeration systems were associated with Danfoss, Copeland, and Dixell, and demonstrated how vulnerabilities in industrial control systems (ICS) can disrupt physical operations without relying on conventional data theft or encryption. The attack also raised concerns about the wider exposure of similar devices, as thousands of refrigeration management interfaces remain accessible from the public internet. The incident highlights the growing risk posed by insecure operational technology (OT), particularly where legacy equipment and remote-management interfaces lack adequate security controls.

What’s Notable and Unique

Researchers identified approximately 2,765 internet-accessible Danfoss AK-SM 800A interfaces during assessment. This figure reflects the scope of that research and should not be interpreted as a current count of exposed devices. Publicly accessible management interfaces increase the opportunity for unauthorized access to industrial equipment.
Research also identified several security flaws in the Danfoss AK-SM 800A platform, including an authentication bypass command injection that could enable remote code execution and a weakness involving web-server configuration changes. Danfoss addressed these findings through firmware updates.
Authorities reported compromised Danfoss AK-SM and AK-SC systems, alongside Copeland XWEB and Dixell XWEB monitoring platforms.

Analyst Comments

The incident demonstrates the business consequences of insufficiently secured industrial infrastructure and reinforces the need to integrate OT security into enterprise risk management. Organizations operating connected facility systems should establish clear ownership of industrial assets, enforce secure remote-access policies, and prioritize remediation based on exposure and operational criticality. The findings also highlight the importance of coordinating security teams with facilities and engineering personnel to ensure that protective measures do not compromise essential operations. A risk-based approach to OT security can help organizations reduce exposure while maintaining the availability and reliability of critical equipment.

Sources

France Supermarket Hacks Expose Risks of Internet-Facing Refrigeration Systems
Freeze the Controller, Defrost the Food: Uncovering Vulnerabilities in Danfoss Refrigeration Controllers
Attackers Heat French Supermarket Fridges Up to 50°C by Hijacking Danfoss Controllers