5 Signs of Ransomware Every UK Business Should Know

Unexpected changes to files across your system are one of the earliest - and most easily ignored - signs of ransomware.

Look Out for These File-Based Red Flags

• Strange file extensions like .lock, .crypt, or .r5a replacing regular formats such as .docx or .pdf. These changes often indicate that encryption is already underway in the background.
• Mass file renaming or disappearance across shared folders or network drives. You might also notice scrambled or corrupted file versions in high-traffic locations.
• Ransom notes or help files appear in affected folders, often named readme.txt or restore_files.html. These usually include instructions for payment in cryptocurrency.

Learn how to train your employees to spot early ransomware activity and report threats before they spread.

Before ransomware strikes, it usually contacts command-and-control servers. It also steals data and starts encrypting files, raising outbound traffic.

Watch for These Tell-Tale Network Behaviours

• Outbound data spikes to unknown IPs, especially from endpoints that usually show steady traffic.
• In double extortion ransomware, attackers encrypt and upload your data. If you don't pay the ransom, they will leak your information.
• Watch for strange port activity or links to blacklisted servers. This could mean someone is accessing your network through a backdoor or moving around inside it.

Understand how a ransomware attack works. This will help you see how attackers use system weaknesses and where you can take action.

Sudden system glitches that aren’t caused by software updates or heavy use might mean ransomware is running in the background.

Signs of Encryption in Progress Include

• Consistently high CPU or disk usage on several endpoints often happens because encryption tools lock files on a large scale.
• Once stable apps are now slow or crashing, disrupting emails, shared files, and cloud tools.
• "Corrupt file" errors or prompts to reinstall programs often hide file encryption as attackers finish their work.

For example, a South Coast engineering firm might suffer total file system failure within two hours of noticing a slowdown. The prompt response handled the threat, but earlier detection could have prevented any downtime.

Unauthorised access is often the precursor to a ransomware attack. Threat actors usually take advantage of weak or stolen credentials. They move across your network, gain higher access, and turn off defences before releasing ransomware.

Key Indicators of Compromised Accounts Include

• Multiple failed login attempts from unknown locations, especially outside regular working hours. These are often signs of brute-force or credential-stuffing attacks.
• Unexpected changes to user roles or permissions can allow attackers to gain admin access, enabling them to escalate privileges and reach critical systems more quickly.
• Locked-out or disabled accounts with no apparent reason. This may be a deliberate tactic to block legitimate users from halting the attack once it begins.

Solace Cyber’s digital forensics experts often find login anomalies weeks before encryption kicks in. Monitoring user access is essential for prevention.

Many ransomware types can spot and turn off security software before they start encrypting files. If your systems suddenly stop reporting, scanning, or alerting, you may already be under attack.

Key Symptoms of Compromised Defences Include

• Antivirus or endpoint protection can stop working, fail to update, or even disappear from devices.
• When security logs go silent, your systems may not warn you about threats. This can happen if logs are disabled or if monitoring tools are uninstalled.
• Firewall rules mysteriously change, allowing traffic to previously blocked domains or IP addresses. This may allow attackers to exfiltrate data without detection.

Learn all about Solace Cyber and how we monitor threats and react, even if your tools are at risk.

If you spot any of these warning signs of ransomware, fast action can prevent widespread damage. The first few hours are critical.

Immediate Response Checklist

• Isolate affected systems from the network to prevent further spread. Disconnect from Wi-Fi, remove Ethernet cables, and disable VPN access where applicable.
• Notify your IT and cybersecurity teams. It’s better to escalate early than risk data loss.
• Check your backups to confirm they’re recent and secure. Ideally, these should be air-gapped and encrypted.
• Do not pay the ransom. There is no guarantee you’ll regain access, and payment can fund further attacks.
• Call in a certified incident response provider. Solace Cyber offers same-day deployment with digital forensics expertise and full compliance support.

Think you’re under attack? Contact our experts today for immediate, confidential support.

Spotting ransomware signs early helps UK businesses prevent major disruptions. Common warning signs include renamed files, unusual login activity, and disabled antivirus. These help organisations respond to threats quickly. However, early detection enables faster recovery, protects data integrity, and minimises costly downtime.

Confidence starts with early detection.

Ransomware isn’t just a cyber threat - it’s a business disruptor, brand risk, and legal liability rolled into one. But with the proper awareness and rapid response plan in place, you don’t have to become the next headline.

By noticing the early warning signs, you can create systems to detect attacks before they happen. This way, you can safeguard sensitive data and keep your operations running smoothly.

Key Takeaways

• Most ransomware attacks show signs before the ransom demand comes. If you recognise these signs early, you can stop the spread before it begins.
• Fast action reduces the scale of impact. The longer ransomware is undetected, the more damage it causes to files, systems, and trust.
• Solace Cyber’s incident response teams work fast and accurately. They use NCSC-recognised protocols to help businesses recover and rebuild quickly.

According to the UK Government’s 2024 Cyber Security Breaches Survey, 59% of medium-sized businesses experienced cyber attacks in the past 12 months - and ransomware remains one of the most disruptive forms reported.

Ready to safeguard your systems and strengthen your resilience? Get your free ransomware risk assessment today! Our experts will check your weak points, review how you respond, and help you prepare before an attack occurs.

Call 01202 308818 or contact our team now. No obligation. No pressure. Just real help when you need it.