Elastio × AWS GuardDuty — Automated scans triggered by GuardDuty malware findings

The False Security of Checked BoxesIn the high-stakes world of cyber-recovery, there is a dangerous assumption that "detection" is a binary state, either you have it or you don’t. Most backup vendors have checked the box by offering anomaly and entropy-based monitoring. But as a CISO who has spent over a decade in regulated industries, I’ve learned that a check-box control is often worse than no control at all. It creates a false sense of security while delivering a signal so noisy and inaccurate that it’s practically unusable. The Inaccuracy Problem: Inference Is Not Evidence The core issue with the ransomware detection provided by backup vendors isn’t just where it happens; it’s how it happens. These tools rely on statistical inference rather than data evidence: Anomaly Detection: Monitors for “unusual” behavior, like a sudden spike in changed blocks or a deviation in backup window duration.Entropy Detection: Measures data randomness to infer encryption. In a modern enterprise, data is naturally “noisy.” Compressed database logs, encrypted video files, and standard application updates all register as anomalies or high-entropy events. Because these tools cannot distinguish between a legitimate .zip file and a ransomware-encrypted .docx, they produce a constant stream of false positives. Figure 1: Modern ransomware (red) operates below the statistical noise floor while legitimate enterprise data generates constant false-positive noise. Elastio detects threats through structural content inspection, independent of entropy. For a SOC team, this noise is toxic. When a tool is consistently inaccurate, the human response is predictable: the alerts are muted, tuned down, or ignored. If your “last line of defense” relies on a signal that your team doesn’t trust, you don’t actually have a defense. Beyond the “Big Bang”: The Rise of Evasive Encryption Current anomaly and entropy tools were designed for the "Big Bang" encryption events of years past. As of 2026, threat actors have evolved well beyond this model, with variants including LockFile specifically engineered to stay below the statistical noise floor using intermittent encryption. Intermittent Encryption: Encrypting every other 4KB block so the overall entropy change remains negligible.Low-Entropy Encryption: Using specialized schemes that mimic the statistical signature of benign, compressed data.Selective Corruption: Attacking only file headers or metadata while leaving the bulk of the file statistically “normal.” Against these techniques, a statistical guess is useless. You need a Data Integrity Control that performs deep content inspection to validate the actual structure of the data, not just its randomness. Mapping Integrity to the Resilience Lifecycle A high-fidelity integrity engine, like Elastio, provides the same level of accuracy regardless of where it is deployed. However, for a CISO, the location of that check is a strategic decision based on the Resilience Lifecycle: The Backup Layer: Validating integrity here is non-negotiable. It ensures that when you hit “restore,” you aren’t re-injecting corrupted data into your environment and extending downtime.The Production Layer (VMs, Buckets, Filers): For mission-critical data, waiting for the backup cycle to run is a luxury we can’t afford. Detecting corruption at the source, in your production VMs, S3 buckets, or filers, is about minimizing the blast radius. Data integrity validation serves different purposes depending on where it is applied in the resilience lifecycle. Scanning production data across VMs, filers, and object stores is the most effective way to minimize blast radius and prevent spread, because it detects corruption before it propagates downstream. When production data cannot be scanned due to security boundaries, operational constraints, or tenancy limitations, snapshots and replicas become the practical control point for achieving the same outcome. In this model, snapshot integrity analysis is not additive to production scanning; it is a substitute. Both serve the same objective: early detection and containment before corruption reaches backups or immutable storage. The CISO’s Bottom Line: Proving vs. Guessing Resilience is measured by the speed and certainty of recovery. Anomaly and entropy-based detection fail on both counts: they are too inaccurate to provide certainty and too late to provide speed. True resilience requires moving from statistical inference to data integrity validation. Whether validating backups to prove recoverability or monitoring production data to prevent spread, the objective is the same: replace guessing with proof. In regulated environments, “recovery is safe” is the only defensible statement a CISO can make to the board. The ability to detect these advanced threats early is the difference between being able to ensure fast recovery versus a ransomware event that results in devastating downtime, data loss, and financial impact.

Cloud ransomware incidents rarely begin with visible disruption. More often, they unfold quietly, long before an alert is triggered or a system fails. By the time incident response teams are engaged, organizations have usually already taken decisive action. Workloads are isolated. Instances are terminated. Cloud dashboards show unusual activity. Executives, legal counsel, and communications teams are already involved. And very quickly, one question dominates every discussion. What can we restore that we actually trust? That question exposes a critical gap in many cloud-native resilience strategies. Most organizations have backups. Many have immutable storage, cross-region replication, and locked vaults. These controls are aligned with cloud provider best practices and availability frameworks. Yet during ransomware recovery, those same organizations often cannot confidently determine which recovery point is clean. Cloud doesn’t remove ransomware risk — it relocates it This is not a failure of effort. It is a consequence of how cloud architectures shift risk. Cloud-native environments have dramatically improved the security posture of compute. Infrastructure is ephemeral. Servers are no longer repaired; they are replaced. Containers and instances are designed to be disposable. From a defensive standpoint, this reduces persistence at the infrastructure layer and limits traditional malware dwell time. However, cloud migration does not remove ransomware risk. It relocates it. Persistent storage remains long-lived, highly automated, and deeply trusted. Object stores, block snapshots, backups, and replicas are designed to survive everything else. Modern ransomware campaigns increasingly target this persistence layer, not the compute that accesses it. Attackers don’t need malware — they need credentials Industry investigations consistently support this pattern. Mandiant, Verizon DBIR, and other threat intelligence sources report that credential compromise and identity abuse are now among the most common initial access vectors in cloud incidents. Once attackers obtain valid credentials, they can operate entirely through native cloud APIs, often without deploying custom malware or triggering endpoint-based detections. From an operational standpoint, these actions appear legitimate. Data is written, versions are created, snapshots are taken, and replication occurs as designed. The cloud platform faithfully records and preserves state, regardless of whether that state is healthy or compromised. This is where many organizations encounter an uncomfortable reality during incident response. Immutability is not integrity Immutability ensures that data cannot be deleted or altered after it is written. It does not validate whether the data was already encrypted, corrupted, or poisoned at the time it was captured. Cloud-native durability and availability controls were never designed to answer the question incident responders care about most: whether stored data can be trusted for recovery. In ransomware cases, incident response teams repeatedly observe the same failure mode. Attackers encrypt or corrupt production data, often gradually, using authorized access. Automated backup systems snapshot that corrupted state. Replication propagates it to secondary regions. Vault locks seal it permanently. The organization has not lost its backups. It has preserved the compromised data exactly as designed. Backup isolation alone is not enough This dynamic is particularly dangerous in cloud environments because it can occur without malware, without infrastructure compromise, and without violating immutability controls. CISA and NIST have both explicitly warned that backup isolation and retention alone are insufficient if integrity is not verified. Availability testing does not guarantee recoverability. Replication can accelerate the blast radius Replication further amplifies the impact. Cross-region architectures prioritize recovery point objectives and automation speed. When data changes in a primary region, those changes are immediately propagated to disaster recovery environments. If the change is ransomware-induced corruption, replication accelerates the blast radius rather than containing it. From the incident response perspective, this creates a critical bottleneck that is often misunderstood. The hardest part of recovery is deciding what to restore The hardest part of recovery is not rebuilding infrastructure. Cloud platforms make redeployment fast and repeatable. Entire environments can be recreated in hours. The hardest part is deciding what to restore. Without integrity validation, teams are forced into manual forensic processes under extreme pressure. Snapshots are mounted one by one. Logs are reviewed. Timelines are debated. Restore attempts become experiments. Every decision carries risk, and every delay compounds business impact. This is why ransomware recovery frequently takes days or weeks even when backups exist. Boards don’t ask “Do we have backups?” Boards do not ask whether backups are available. They ask which recovery point is the last known clean state. Without objective integrity assurance, that question cannot be answered deterministically. This uncertainty is not incidental. It is central to how modern ransomware creates leverage. Attackers understand that corrupting trust in recovery systems can be as effective as destroying systems outright. What incident response teams wish you had is certainty What incident response teams consistently wish organizations had before an incident is not more backups, but more certainty. The ability to prove, not assume, that recovery data is clean. Evidence that restoration decisions are based on validated integrity rather than best guesses made under pressure. Integrity assurance is the missing control This is where integrity assurance becomes the missing control in many cloud strategies. NIST CSF explicitly calls for verification of backup integrity as part of the Recover function. Yet most cloud-native architectures stop at durability and immutability. When integrity validation is in place, recovery changes fundamentally. Organizations can identify the last known clean recovery point ahead of time. Recovery decisions become faster, safer, and defensible. Executive and regulatory confidence improves because actions are supported by evidence. From an incident response standpoint, the difference is stark. One scenario is prolonged uncertainty and escalating risk. The other is controlled, confident recovery. Resilience is proving trust, not storing data Cloud-native architecture is powerful, but ransomware has adapted to it. In today’s threat landscape, resilience is no longer defined by whether data exists somewhere in the cloud. It is defined by whether an organization can prove that the data it restores is trustworthy. That is what incident response teams see after cloud ransomware. Not missing backups, but missing certainty. Certainty is the foundation of recovery And in modern cloud environments, certainty is the foundation of recovery.

CMORG’s Data Vaulting Guidance: Integrity Validation Is Now a Core Requirement In January 2025, the Cross Market Operational Resilience Group (CMORG) published Cloud-Hosted Data Vaulting: Good Practice Guidance. It is a timely and important contribution to the operational resilience of the UK financial sector. CMORG deserves recognition for treating recovery architecture as a priority, not a future initiative. In financial services, the consequences of a cyber event extend well beyond a single institution. When critical systems are disrupted and recovery fails, the impact can cascade across customers, counterparties, and markets. The broader issue is confidence. A high-profile failure to recover can create damage that reaches far beyond the affected firm. This is why CMORG’s cross-industry collaboration matters. It reflects an understanding that resilience is a shared responsibility. Important Theme: Integrity Validation The guidance does a strong job outlining the principles of cloud-hosted vaulting, including isolation, immutability, access control, and key management. These are necessary design elements for protecting recovery data against compromise. But a highly significant element of the document is its emphasis on integrity validation as a core requirement. CMORG Foundation Principle #11 states: “The data vault solution must have the ability to run analytics against its objects to check integrity and for any anomalies without executing the object. Integrity checks must be done prior to securing the data, doing it post will not ensure recovery of the original data or the service that the data supported.” This is a critical point. Immutability can prevent changes after data is stored, but it cannot ensure that the data was clean and recoverable at the time it was vaulted. If compromised data is written into an immutable environment, it becomes a permanently protected failure point. Integrity validation must occur before data becomes the organization’s final recovery source of truth. CMORG Directly Addresses the Risk of Vaulting Corrupted Data CMORG reinforces this reality in Annex A, Use Case #2, which addresses data corruption events: “For this use case when data is ‘damaged’ or has been manipulated having the data vaulted would not help, since the vaulted data would have backed up the ‘damaged’ data. This is where one would need error detection and data integrity checks either via the application or via the backup product.” This is one of the most important observations in the document. Vaulting can provide secure retention and isolation, but it cannot determine whether the data entering the vault is trustworthy. Without integrity controls, vaulting can unintentionally preserve compromised recovery points. The Threat Model Has Changed The guidance aligns with what many organizations are experiencing in practice. Cyber-attacks are no longer limited to fast encryption events. Attackers increasingly focus on compromising recovery, degrading integrity over time, and targeting backups and recovery infrastructure. These attacks may involve selective encryption, gradual corruption, manipulation of critical datasets, or compromise of backup management systems prior to detonation. In many cases, the goal is to eliminate confidence in restoration and increase leverage during extortion. The longer these attacks go undetected, the more likely compromised data is replicated across snapshots, backups, vaults, and long-term retention copies. At that point, recovery becomes uncertain and time-consuming, even if recovery infrastructure remains available. Why Integrity Scanning Must Happen Before Data Is Secured CMORG’s point about validating integrity before data is secured is particularly important. Detection timing directly affects recovery outcomes. Early detection preserves clean recovery points and reduces the scope of failed recovery points. Late detection increases the likelihood that all available recovery copies contain the same corruption or compromise. This is why Elastio’s approach is focused on integrity validation of data before it becomes the foundation of recovery. Organizations need a way to identify ransomware encryption patterns and corruption within data early for recovery to be predictable and defensible. A Meaningful Step Forward for the Industry CMORG’s cloud-hosted data vaulting guidance represents an important milestone. It reflects a mature view of resilience that recognizes vaulting and immutability as foundational, but incomplete without integrity validation. The integrity of data must be treated as a primary control. CMORG is correct to call this out. It is one of the clearest statements published by an industry body on what effective cyber vaulting must include to support real recovery.