You think EDR keeps you secure? Think again.

Cybercriminals have found a new way to bypass Endpoint Detection Response solutions from some of the top vendors by deploying EDR killers that make it easier for them to deploy ransomware or any other malicious software by evading the detection mechanisms in place.

Let us explore what EDR killers are and how cybercriminals are using EDR killers to orchestrate undetectable and persistent ransomware attacks.

What is an EDR Killer?

EDR killers are malicious tools designed to evade Endpoint Detection and Response solutions, enabling attackers to deploy ransomware (or any other malware), move laterally within the network, exfiltrate data, and create a backdoor through compromised systems.

There is a rise in ransomware groups using EDR Killer in their attacks, with the most used EDR killers including EDRKillShifter (developed by RansomHub), RealBlinding EDR (A customized version developed by Crypto24), EDRSilencer, and HRSword.  

As per cybersecurity experts, these groups are repurposing legitimate tools to make their ransomware attack campaigns more persistent and undetectable. For example, RealBlindingEDR is highly customized by Crypto24. 

The following are ransomware groups known to use EDR killer more frequently:

• RansomHub – initially linked to the development of EDR killer tool
• Blacksuit
• Medusa
• Quilin
• Dragonforce
• Crytox
• Lynx
• INC
• Crypto24

the latest ransomware that has targeted nearly two dozen companies in US Europe and Asia, since April. It uses customized tools with legitimate tools to carry out undetectable attacks.

Some facts worth considering

• There is a 37% rise in ransomware in all the data breaches compared to last year (Verizon DBIR 2025).
• 89% of all breaches on SMBs were ransomware-based (Verizon DBIR 2025).
• Among all the ransomware groups, RansomHub had the most victims over the last year, with 833. (Threatlabz ransomware report 2025).
• Over the past few months, Ransomware gangs using EDR killers have targeted large organizations from sectors like technology, finance, and entertainment in the US, Europe, and Asia (Trend Micro).

How does a typical EDR Killer work?

A typical EDR works by deploying multiple techniques to evade EDR detection. For example, EDRSandblast works in the following way:

• They disable callback mechanisms used by EDRs to monitor system activity.
• Remove hooks in process memory to monitor API calls.
• Remove all the security measures and protections around processes like LSASS.

How does an EDR Killer attack work?

Initial access

Phishing, exploitation of software vulnerabilities, or usage of a compromised system to gain access

EDR disabling

Attacker uses a customized EDR killer variant (like EDRSandbox, Real BlindingEDR) to target and terminate EDR and other antivirus processes to evade detection, creating a blind spot for the attacker to exploit.

Deployment of malware

Once protection mechanisms are disabled, the attackers deploy malware and other malicious software without raising alerts.

Groups like Crypto24 maintain persistence by creating and activating default admin accounts on Windows systems after gaining initial access.

What makes it dangerous?

The following are some of the aspects that make EDR killer-based attacks more dangerous than other attacks:

• Since they use tools and scripts that are already present in the target systems, they get past even some of the renowned detectors from vendors like Malwarebytes, Bitdefender, Kaspersky, Trend Micro, Broadcom/Symantec, Sentinel One, and Citrix.
• They work within the memory without needing to write files to the disk, which makes them harder to detect using file-based scanning methods.
• They directly target EDR agents, disabling or modifying them to evade detection using multiple methods like killing EDR processes, tampering with the agent configuration, or exploiting vulnerabilities.
• Attackers poison ML-based detection models, allowing the attacks to even evade ML-based detections.

Preventive measures that can be implemented against EDR attacks

The following are some of the measures that can be used to prevent EDR-killer-based attacks:

Configure EDR

Ensure that your EDR is configured and managed to deal with such threats. Take the assistance of experts to help you configure your EDR to detect any malicious code abusing vulnerable drivers.

Establish a mechanism to alert on EDR tampering

Deploy a mechanism that could detect any form of tampering of the EDR solution that instantly alerts on any suspicious activity, preventing unauthorized disablement of EDR.

Check for any known file hashes

Check for any known file hashes relevant to commonly used EDR Killers, like EDRSandblast and RealBlindingEDR.

Establish and implement policies and controls

Create and implement strict controls on driver loading and enforce kernel-mode code signing. Harden application control by creating a policy that only allows selected drivers to load.

Monitor for potentially unsafe applications

Continuously monitor the infrastructure for any recent installation of legitimate or potentially unsafe application(s).

Keep patch management in check

Instead of bringing their own vulnerable driver, attackers often exploit those already present. Therefore, it is critical to keep the effectiveness of patch management processes in check.

Restrict access to security settings

Restrict access to endpoint security settings, protect them with a strong password, and add layers of protection over them, making it difficult for unauthorized actors to alter the settings.

Layer your defense

EDR-only defense is more susceptible to the risk of being compromised. Therefore, it is critical to layer defense with the help of cybersecurity experts.   

Focus on cybersecurity hygiene

Don’t lose focus on cybersecurity hygiene and mitigating alert fatigue. EDR Killer attacks require the security team’s increased focus to respond to threats and prepare defenses for an early detection of attacks, for a quick response to threats before the attackers move to further stages of the attack.