Researchers Uncover RealBlindingEDR Tool in Active Campaigns

Security reporters documented a new tool named RealBlindingEDR that removes kernel callback registrations and related hooks on Windows systems, behavior that disables or severely degrades many antivirus and EDR functions. The tool’s public repository and multiple vendor/industry write-ups confirm its existence and explain how it manipulates kernel registration callbacks.

Kernel Callback Removal

RealBlindingEDR targets kernel registration points that security products use to inspect and control system activity. Specifically, the tool removes or clears callback registrations such as object manager callbacks, process/thread creation callbacks, minifilter callbacks, and image-load notifications. When adversaries run the tool with elevated privileges, EDR and AV agents lose reliable visibility into process creation, image loads, file-system hooks, and related telemetry. The GitHub repository shows the tool’s intent and the specific callback vectors it addresses.

EDRs Rely on Those Callbacks

EDR and AV vendors use kernel callbacks to intercept suspicious behavior before attackers establish persistence. When an actor clears those callbacks, the endpoint loses a primary detection mechanism. Therefore, defenders see fewer or no alerts. The industry already observed similar tactics in multiple incidents where attackers disabled or uninstalled protection before executing ransomware or data theft. Vendors and research groups debate detection strategies because the approach exploits legitimate kernel APIs rather than a single product bug.

Researchers found a public GitHub repository that documents RealBlindingEDR’s behavior. Reporters also observed chatter about the tool on underground forums and on monitoring feeds for attacker tooling. Meanwhile, security vendors link the general class of EDR-killer tools to recent ransomware campaigns, where actors either use open-source utilities or create bespoke versions. Consequently, defenders should treat the presence of such a tool as a high-risk sign of post-exploitation activity on any host.

“EDR Killers” in Ransomware Campaigns

Multiple analysts and vendors report that several ransomware groups now include EDR-disabling techniques in their playbooks. Researchers observe that groups combine living-off-the-land tooling, driver abuse, and custom utilities to neutralize protections before deploying final payloads. Trend reports and incident writeups show that threat actors deploy these tactics in the wild, which raises the operational urgency for defenders.

RealBlindingEDR often uses in-memory operations and legitimate kernel APIs rather than dropping obvious executable files. Therefore, signature-based detection fails frequently. Instead, defenders must detect abnormal behaviors: sudden loss of EDR heartbeats, unexpected removal/deregistration of callbacks, unusual handle operations, or missing event streams that previously existed on healthy endpoints. Furthermore, attackers may chain callback removal with credential theft or lateral-movement tools to maximize impact.

Harden, Monitor, and Assume Compromise

First, enforce least privilege so adversaries cannot run privileged tooling casually. Second, require driver signing and enable kernel integrity features where possible. Third, instrument multi-layer telemetry: correlate endpoint health, EDR heartbeats, network flows, and identity logs. Fourth, treat sudden EDR absence as an incident trigger to isolate hosts and triage. Finally, patch and monitor for known vulnerable drivers that attackers could abuse to gain kernel-level capabilities. Multiple vendor advisories and government writeups outline these steps

Security vendors and national agencies have published guidance on the broader EDR-killer threat class and on specific incidents that used similar techniques. Researchers urge defenders to adopt defense-in-depth and to validate EDR integrity with out-of-band checks. Moreover, defenders should subscribe to vendor- and government-issued advisories for detection rules and IOCs that researchers publish.

Treat EDR Blindings as Active Incidents

RealBlindingEDR and similar tools demonstrate that attackers now weaponize operating-system mechanisms to remove defenders’ sightlines. Therefore, security teams must assume that any successful post-exploitation action could attempt to blind agents. To reduce risk, teams should implement rapid isolation workflows, multiple telemetry sources, and strict control over who can run privileged code.

FAQs 

Q1. Is RealBlindingEDR a zero-day in antivirus products?
No. The tool uses documented kernel APIs to remove callbacks; it exploits how EDRs use those APIs rather than a single product flaw. The GitHub repo shows callback removal rather than an unknown bug. 

Q2. Did a specific vendor discover this?
No single vendor, reporting comes from security news sites, repository evidence, and vendor advisories about the EDR-killer trend. 

Q3. How can defenders detect the tool?
Look for missing EDR telemetry, abnormal handle operations, and kernel callback deregistration events. Also, correlate with network and authentication anomalies. 

Q4. Should teams remove EDRs because of this?
No. EDRs still provide critical telemetry; instead, add complementary layers (network detection, immutable logging) and validate EDR integrity continuously.

Q5. Is RealBlindingEDR actively used in ransomware?
Public reporting connects the EDR-killer pattern to live ransomware campaigns. Researchers warn that some groups use public code or custom variants in active operations.