High

DLL Search Order Hijacking in ESET Command-line Scanner

IdentifiersCVE-2024-11859CWE-427· Uncontrolled Search Path Element

CVE-2024-11859 is an insecure DLL loading vulnerability in ESET Command-line Scanner (ecls/ecls.exe). According to the provided content, the scanner loads version.dll by searching the current working directory before trusted system directories, allowing DLL search order hijacking/proxying. An attacker who can place a malicious version.dll in a directory from which ecls is executed can cause ecls.exe to load the attacker-controlled DLL alongside the legitimate system version.dll. In observed exploitation, ToddyCat used a malicious 64-bit version.dll (TCESB) that exported functions forwarding to the legitimate Windows version.dll while executing attacker code in the trusted ESET process context.

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ANALYST BRIEF

Impact, mitigation & remediation

What it means. What to do now. Patch path, mitigations, and the assume-compromise checklist.

Impact

What an attacker gets, and what they’ve been doing with it.

Successful exploitation allows execution of attacker-controlled code inside the ESET Command-line Scanner process. In the reported intrusions, this was used to launch the TCESB malware, which then decrypted and executed additional payloads from memory and facilitated further defense evasion activity. Because the content specifically states exploitation required administrator privileges, the practical impact described here is code execution in a trusted security-product process for an attacker already holding administrative access, improving stealth and enabling follow-on malicious actions.

Mitigation

If you can’t patch tonight, do this now.

Until patching is fully deployed, reduce exposure by preventing execution of ecls from attacker-writable directories, restricting administrative access, monitoring for unexpected version.dll files in working or temporary directories, and alerting on unsigned or anomalous DLL loads by ecls.exe. Additional detection opportunities mentioned in the content include monitoring for installation of vulnerable drivers, unexpected Microsoft symbol server/PDB downloads, and suspicious library loads associated with the scanner process.

Remediation

Patch, then assume compromise.

ESET patched the vulnerable ecls component on January 21, 2025. Remediation is to update ESET Command-line Scanner/ecls to the vendor-fixed version referenced in ESET's security update/advisory. Ensure the patched ecls binary is deployed everywhere the command-line scanner is used.

PUBLIC EXPLOITS

Exploits

No public exploits tracked yet. Mallory keeps watching.

VALID 0 / 0 TOTALView more in app

No public exploit code observed for this vulnerability.

ACTIVITY FEED

Recent activity

2 sources tracked across advisories, community write-ups, and news. New activity surfaces here as Mallory finds it.

2 SOURCESView more in app

the hacker newsNews

Nov 25, 2025

ToddyCat's New Hacking Tools Steal Outlook Emails and Microsoft 365 Access Tokens

A security flaw in ESET Command Line Scanner that was exploited by the ToddyCat threat actor to deliver malware (TCESB).

securelistNews

May 13, 2021

APT group ToddyCat exploits a vulnerability in ESET for DLL proxying | Securelist

An insecure DLL loading vulnerability in the ESET Command-line scanner (ecls) that can cause a malicious version.dll to be loaded from the current directory instead of the legitimate system library, enabling code execution in the trusted security process context.

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Exposure mapping

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Threat actor evidence1

Every observed campaign linking this CVE to a named adversary.

Associated malware2

Malware families riding this exploit, with evidence and IOCs.

Detection signatures

YARA, Sigma, Snort, and vendor rules, auto-deployed to your SIEM.

Vendor-by-vendor mapping

Cross-references every affected SKU, including bundled OEM variants.

Social activity