Data-Level Detection: Anomaly or Encryption
Ransomware attacks continue to bypass traditional security layers, including endpoint detection and server-based defenses. Businesses are adding data-layer detection as an extra safeguard against ransomware.
However, a problem exists: most of these solutions do not work.
Most solutions rely on anomaly detection, which is no longer an effective approach.
Today, instead of accurately detecting ransomware, this method:
- Floods security teams with false positives
- Misses modern ransomware techniques that bypass anomaly-based detection.
- Fails to provide actionable intelligence past anomaly alerts.
To detect ransomware, you must recognize actual encryption activity in data—not just alert on statistical anomalies.
In this blog, we break down:
- Why anomaly detection fails to stop ransomware
- Weaknesses of anomaly-based detection
- Why encryption detection is the reliable solution
1. What is Anomaly Detection?
Anomaly detection identifies unusual behavior in data patterns to detect potential ransomware activity. It is commonly implemented in backup solutions using:
Change Rate Analysis – Detects unusual spikes in modified data. Backup Size Monitoring – Flags abnormal increases in backup size. Metadata Analysis – Looks for mass renaming or restructuring of files. Entropy Detection – Identifies high randomness in file contents (potential encryption).
While these techniques seem logical, they do not stop ransomware in practice.
2. Where Anomaly Detection Falls Short
(A) Many False Positives
Anomaly detection is inherently noisy because it cannot distinguish between a real threat and normal data fluctuations.
- SOC teams receive an average of 4,484 security alerts daily—67% are ignored due to alert fatigue.
[The Silent Threat of Alert Fatigue] - When false positives are constant, teams either turn off or ignore them
Key takeaway: A detection system that creates too many alerts can be as bad as having no detection.
(B) Lack of Precision: No Actionable Insights
Anomaly detection does not tell you what’s happening—only that something “looks unusual.”
- Security teams are left investigating vague alerts instead of getting concrete, actionable insights.
- When ransomware is actively spreading, you don’t have time to analyze anomalies—you need to know precisely what is encrypting your data.
Key takeaway: A detection system that only says “something might be wrong” can create more work than solving the problem.
(C) Arbitrary Sensitivity Settings Undermine Effectiveness
Security teams are responsible for tuning sensitivity levels to deal with alerts, which is an unreliable process.
- Set sensitivity too high? Teams are flooded with false positives.
- Set sensitivity too low? Ransomware slips through undetected.
- Since every environment is different, there’s no universal threshold, leaving teams guessing and making detection inconsistent and useless at best.
Key takeaway: A detection system that requires constant manual tuning is fundamentally flawed.
(D) False Negatives: How Ransomware Evades Anomaly Detection
Many modern ransomware families are designed to evade anomaly detection.
- Several top ten ransomware variants use intermittent encryption—encrypting parts of files instead of the entire file—so entropy remains unchanged.
- Attackers test their ransomware against anomaly detection tools before deploying it, ensuring their malware remains undetected.
- Examples of Ransomware That Evade Anomaly Detection: LockFile – Uses partial encryption, modifying only parts of files to avoid detection. Xorist – Does not change metadata to bypass statistical anomaly-based defenses. Alcatraz Locker – Base64 encoding, ensuring minimal entropy changes.
Sources:
LockFile ransomware’s box of tricks: intermittent encryption and evasion – Sophos News
Key takeaway: If attackers can trivially bypass your anomaly detection method, it’s not a real ransomware defense.
(E) Anomaly Detection Doesn’t Look for Malware
Anomaly detection does not detect actual ransomware executables—it only flags suspicious behavior.
Gartner confirms this:
“It’s important to note that anomaly scanning does not detect malware executables and cannot prevent those executables from becoming part of the backup of a system.”
Secure Your Backup Platforms and Data From Ransomware Attacks, 2024
- This means ransomware can still be backed up, spread, and restored—even if anomaly detection exists.
Key takeaway: A system that cannot detect actual ransomware encryption is broken, and their data is at risk.
3. The Solution: Ransomware Encryption Detection
Elastio Ransomware Recovery Assurance Platform is Different
Instead of relying on anomaly detection, Elastio Ransomware Recovery Assurance Platform (Elastio Platform) uses encryption-based detection to recognize actual ransomware activity inside storage and backups.
Elastio Platform leverages a proprietary Machine Learning (ML) model built on a dataset of all known ransomware since 2014. Elastio Platform can identify ransomware encryption in data, even for zero-day threats that have not yet been identified.
Key Differentiators of Elastio Platform’s Approach:
Detects the specific ransomware variant encrypting at the file level Identifies zero-day ransomware that has never been seen before with 99.99% accuracy Provides forensic insights on the attacker’s tactics Eliminates false positives by focusing on real encryption activity
With Elastio Platform, security teams don’t have to guess. When ransomware is detected, Elastio Platform knows what’s happening, which files are affected, and how to respond.
Conclusion: The Need for Ransomware Detection
Anomaly detection was never designed to stop ransomware. The only way to reliably detect ransomware is by recognizing how and when ransomware has encrypted data
Elastio Platform detects actual ransomware encryption, providing precise and actionable intelligence
Eliminate noise. Gain intelligence with Elastio Platform to be proactive and defend against ransomware
