Ransomware is malicious software that blocks access to your data. Attackers sneak in and hold your files hostage until you pay up to get access back. They might even threaten to leak sensitive information if you say no. Of course, cybercriminals aren’t trustworthy, and they still might do it even if you say yes. It’s always a lose-lose in any scenario. 

Many organizations find they’re a victim after they are locked out of their data and systems stop working, which is exactly why effective ransomware detection is so important. The longer threat actors can move around in your environment and find your most important data, the more damage they can do to your business.

Not Fun Fact: In 2024, ransomware was involved in 9.5% of all observed incidents across environments monitored by Huntress.

The scary part about ransomware is that it can lurk in your environment before ever revealing itself. Some strains spread through your defenses through phishing emails with malicious attachments, users lured to bad websites, and attackers abusing remote access tools. 

Signs of ransomware can include:

• Encrypted files with strange extensions

• Apps or files that refuse to open

• A sudden spike in CPU or disk use, especially on systems that store critical data

• Folders you can normally access are now locked or hidden

A big part of how to detect ransomware is using the right mix of monitoring and detection. Basic antivirus software might get lucky and detect a well-known strain of ransomware, but you often need specialized ransomware detection tools that look for the signs of ransomware activity rather than just known signatures. Remember that attackers constantly tweak their code to avoid being detected. If your security strategy relies only on antivirus software, you’ll likely miss a ransomware attack.

Maybe—but don’t rely on traditional antivirus alone. Attackers are clever, and they know how to trick antivirus software that relies on signature-based detection. Plus, some ransomware strains are fileless, meaning they don’t leave the typical footprints that antivirus tools look for. They may run in memory and take advantage of existing system tools.

That doesn’t mean antivirus is useless, of course. It still catches known variants and can block many run-of-the-mill threats. But you're gambling if you rely solely on antivirus. Combining it with other measures, like endpoint detection and response (EDR), is the best approach. These advanced tools can flag the suspicious commands or processes that often happen right before full encryption begins.

1. Watch for baseline activity: Watch what normal, day-to-day usage looks like. If you suddenly see many file modifications, unexpected CPU spikes, or strange network connections on endpoints in your organization, something’s sketchy.

2. Spot abnormal file changes: Ransomware often renames or encrypts files in bulk. A good EDR tool checks for unusual rename patterns or large file movements, helping you spot the intrusion early.

3. Use canaries: Plant decoy files. If attackers try to encrypt those files, you get an immediate alert. This has become a go-to in ransomware detection toolsbecause it gives you a clear sign that you’re under attack.

4. Keep logs and alerts front and center: Log management can help you spot small anomalies that, when added up, make a big problem. If you spot repeated failed login attempts on multiple machines or commands that nobody on your team would ever need to run, a ransomware attack may be in the works.

If ransomware slips past your perimeter, that first alarm can mean the difference between quickly isolating a device versus watching systems shut down before your eyes. 

Keep in mind that attackers don’t usually tell on themselves. They’re world-class poker players that way. They play it cool, hiding out, waiting for the right time to strike. They only show their hand when they’re ready to encrypt or steal critical files. You need to constantly watch for the tells so you can catch them in the act, not after the fact.

Knowing how to detect ransomware is one thing—doing it is another.Huntress Managed EDR goes beyond signatures or basic antivirus. We watch your endpoints around the clock, scanning for strange processes and bad behaviors. With strategies like ransomware canaries, we catch encryption attempts early, so the attack is contained before it spreads and causes an impact.

Our 24/7 Security Operations Center (SOC) of elite first responders reviews alerts and suspicious behaviors so you don’t have to. If we see signs of ransomware, we’ll help isolate compromised machines and stop further damage. 

Ransomware is only getting bolder, but you can beat it. Huntress Managed EDR helps you spot the early warning signs and lock down your environment before attackers can lock you out.