Sinobi Ransomware
Under attack by ransomware or suffering a cyber breach?
Speed is critical when facing a live cyber attack. If you believe you have been compromised by the Sinobi ransomware group or another threat actor, contact us immediately.
About Sinobi ransomware group
The Sinobi ransomware group has been observed targeting organisations primarily across Asia and Europe, with activity suggesting a financially motivated approach rather than ideological or political intent. Known victims span various industries, including manufacturing, construction materials, professional services, healthcare, and education.
Public reporting on Sinobi remains limited, though available intelligence indicates the use of established ransomware tooling rather than bespoke malware. Sinobi represents a newer presence within the broader ransomware landscape, operating alongside other emerging ransomware groups rather than as a long-established threat.
Sinobi activity has included claims of victim data theft and the use of leak sites hosted on Tor-based infrastructure, suggesting the adoption of double extortion tactics consistent with modern ransomware operations.
What we can help with:
- Encrypted files & ransomware data recovery
- Incident response and containment
- Secure data restoration and system recovery
- Use of ransomware decryption tools and data recovery software
- Development of incident response plans and disaster recovery solutions
- Post-incident reviews and security hardening
Request a call back
If your organisation has been infected with ransomware contact us immediately.
How Sinobi operators work
Sinobi operators typically gain initial access through phishing emails, compromised remote access credentials, or credential access obtained via prior malware infections or underground forums. Once inside the environment, attackers perform basic reconnaissance to identify valuable systems, file shares, and sensitive data.
Privilege escalation and lateral movement are used to facilitate ransomware deployment across shared network drives and critical systems. In some incidents, attackers have modified system processes or used scripting interpreters to bypass security tools and impair defences.
Ransomware is then deployed to encrypt files using strong encryption methods, including AES-128-CTR. Files may be marked with a Sinobi file extension, desktop wallpaper changes may be applied, and ransom notes are generated to demand payment. Shadow copies and recycle bin contents may be removed to make recovery more difficult.
We are equipped to deal with an attack from any ransomware group.
Don’t hesitate to contact us if you are under attack from a ransomware group not listed above.
Recognising a Sinobi attack
A Sinobi ransomware incident is typically identified by encrypted files, ransom notes appearing across affected systems, and sudden operational disruption. Organisations may also observe suspicious authentication activity, abnormal system processes, or unexpected use of removable media prior to encryption.
In some cases, evidence of data exfiltration to cloud storage or external servers may be present before encryption begins.
Why you must not interfere with your ransomware environment
If you discover a physical break-in at your offices, your first instinct would be to call the police; touch nothing and let them search for clues. Then, your focus would shift to restoring business operations.
A cyber-attack requires the same approach. Your digital environment is a CRIME SCENE. It is crucial to leave the environment untouched to allow for a forensic investigation.
This is not a task for your IT team or MSP. Digital Forensic specialists are available 24/7 to assist you, just like in a physical crime.
Known threat actors
Ransomware groups behind the attacks
Below is a breakdown of the most active ransomware groups and the variants driving their attacks.
Post breach actions
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Call a NCSC Cyber Incident Response approved supplier Some NCSC providers will fund up to 48 hours of investigation into your incident.
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Report the incident to Report Fraud
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Locate your business continuity plan Work out what you can do without access to your systems and data.
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Identify your business insurance contact details
Who are we and what experience do we have in responding to cyber incidents?
We are accredited to ISO 27001 and recognised by the UK’s National Cyber Security Centre (NCSC).
We provide comprehensive cyber risk management services, with a core focus on Digital Forensics and Incident Response (DFIR). Our capabilities are driven by a 24/7 Security Operations Centre and a dedicated in-house intelligence team that delivers timely, actionable threat reporting.
With decades of collective cyber security experience, we have the expertise to assume operational ownership of your entire IT security architecture – simplifying and strengthening cyber security across your business.
As an Assured Service Provider for Cyber Incident Response (CIR) at the Standard Level. This accreditation demonstrates our ability to deliver high-assurance, effective support in response to a wide range of cyber threats.
Your NCSC-approved supplier is a specialist crime scene investigator who will:
- Isolate and preserve your environment for forensic investigation.
- Identify where the data has been duplicated and issue a legal takedown order.
- Identify your data, application and systems restore points. These might be at different points in time and will need to be carefully restored and reconstructed in a pristine environment.
- Liaise with your business insurance company and if needed, with the Police.
- Advise you on notifying your customers of your situation.
- Rebuild your systems, restore your data and get you back to full operation. Note: This process can take between 2 weeks – 2 months.
Working with us
Our response process
Our team are ransomware recovery specialists with a proven, streamlined approach to resolving incidents quickly and effectively.
Step 1: Triage
We deploy our incident response team the same day. From the first call, we begin onboarding, introduce key stakeholders, set communication schedules, and start gathering critical information to guide the response.
Step 2: Investigation
DFIR (Digital Forensic Incident Response) teams investigate breaches to identify vulnerabilities, attack vectors, and system impacts from ransomware such as Data Loss (PII). We deliver clear forensic insights to guide mitigation.
Step 3: Contain
Our onsite and remote teams act fast to stop the attack in its tracks. That includes isolating affected systems, removing malicious code, and putting protections in place to prevent further spread or damage.
Step 4: Remediate & Eradicate
Once contained, we work to fully eliminate the threat. This includes fixing exploited vulnerabilities, restoring systems to a secure state, and ensuring no traces of the attack remain.
Step 5: Recover
Our incident response teams help get your business back to normal. We restore access to systems, recover data, and ensure services are safe, stable, and functioning, with minimal downtime.
Step 6: Post Incident
We conduct a full review of the incident response and recovery efforts. Together we assess what happened, what worked, and what can be improved, helping you build stronger defences for the future.
Forensic analysis to drive recovery
Our process includes a thorough digital forensic analysis from step two where the output becomes a central component of business recovery. This is because understanding the attack is of critical importance:
Informing an initial infection date
The extent and spread of infection
Data exfiltration having an impact on regulatory positions
Ensuring that the attacker and any tooling or artefacts they leave behind are eradicated
It is critical that the analysis of digital evidence is carried out to an agreed plan.
Maximising early root cause discovery and legal leverage
The process is purpose-built to uncover the root cause as early as possible, which is essential to inform remediation / eradication and recovery as well as supporting a legal take-down case if this is applicable. A legal take-down means we can assist in the legal enforcement that stops the criminals from publishing the data, thus undermining the ransom notice.
Our Digital Forensic and Incident Response (DFIR) teams maintain consistent communication throughout. Dedicated Incident Managers and technical engineering leads provide updates during the Cyber Incident Response journey, utilising risk registers and working within change management processes, all from triage through to post-incident, delivering successful business recovery.
Key take aways
- You will not be able to access your systems or data.
- It is advised to disconnect from the internet and shut down your systems, including PCs, to prevent further infections.
- Your Office 365 system might also be compromised, allowing the attackers to monitor your responses. Avoid communicating with individuals through your primary email or team systems.
- Threat actors typically infiltrate your system at least 2-4 weeks before you become aware of the attack. Your data will have already been exfiltrated. If your system is encrypted, this was not an overnight event.
- Ransom demands in the UK typically range from £500,000 to £3 million, with some sectors, like education, facing demands that exceed £5 million
- Paying the ransom may violate financial sanctions, which is a criminal offence and could result in a custodial sentence or further financial penalties.
- If your data is sold or published online, it puts your customers and staff at risk, potentially implicating you in a Data Protection breach.
- You will need to submit a data takedown request to the initial location where the data was transferred.
- Do not overwrite the encrypted data. It is crucial to determine when the infection began and where the data was sent.
- Avoid rebuilding from the latest backup, as it is likely to be infected.
Why should I trust Zensec to do this work rather than my IT team?
A forensic analysis needs to be meticulous and a clean restore and recovery requires a wealth of experience not normally available in an in-house team who must provide a broader range of IT support skills:
Internal IT teams don’t have the necessary skill set to resolve security encryption issues themselves.
IT teams may recover to the same position with indicators of compromise ready to do it again… which can lead to another breach.
Internal teams are pressured to restore business operations and may recover before forensic analysis even begins, potentially destroying the crime scene before completion.
We can help
Frequently asked questions
Key information when you’re under pressure.
Initial access is commonly achieved through phishing emails, compromised credentials, or credential access obtained from prior infections or underground forums.
Sinobi is considered part of the evolving ransomware landscape, representing an emerging group that uses established ransomware techniques rather than highly bespoke tooling.
Sinobi ransom notes provide payment instructions, deadlines, and warnings about data leaks. Notes may be accompanied by file extensions applied to encrypted files and changes to desktop wallpaper.
The individuals behind Sinobi remain unidentified. Reporting suggests financially motivated threat actors operating within the broader ransomware threat ecosystem, with some indications of Eastern European origins, though attribution remains unconfirmed.
Dealing with a ransomware attack?
Our ransomware recovery service can help
Our expert team works quickly to contain the breach, recover your data, and restore your systems to full operation. We’ll guide you through every step of the recovery process and help strengthen your defences to prevent future attacks. Regain control with Zensec - trusted support when it matters most.

