{"Id":"0144dbef-1da8-406c-8e35-7afee57dc471","Author":"Michael Haag","Created":"2025-03-26","MitreID":"T1068","Category":"vulnerable driver","Verified":"TRUE","Commands":{"Command":"sc.exe create isodrivep64.sys binPath=C:\\windows\\temp\\isodrivep64.sys type=kernel && sc.exe start isodrivep64.sys","Description":"ABYSSWORKER is a malicious driver used in MEDUSA ransomware attacks to disable EDR systems. The driver masquerades as a legitimate CrowdStrike Falcon driver and provides extensive capabilities to terminate processes, remove security callbacks, manipulate files, and disable security tools. It uses stolen certificates from Chinese companies and requires a specific password for activation. The driver was observed being deployed alongside HEARTCRYPT-packed loaders and provides attackers with kernel-level capabilities to blind EDR products by removing notification callbacks, detaching mini-filter devices, and replacing driver major functions.","Usecase":"Elevate privileges","Privileges":"kernel","OperatingSystem":"Windows 10"},"Resources":["https://www.elastic.co/security-labs/abyssworker"],"Acknowledgement":{"Person":"","Handle":""},"Detection":[],"KnownVulnerableSamples":[{"Filename":"","MD5":"9085c848e3b632fdc01cf64d95d3e0fc","SHA1":"75f86bdfb72543acc52e4903ba36c3a1a35e8399","SHA256":"1e42c8cb410a7ed653cfe62bbd8cf191f31a47337fe1ffcc35232d03f2da05ef","Signature":"","Date":"","Publisher":"","Company":"CrowdStrike, Inc.","Description":"CrowdStrike Falcon Sensor Driver","Product":"CrowdStrike Falcon Sensor","ProductVersion":"6.34.14806.0","FileVersion":"6.34.14806.0","MachineType":"AMD64","OriginalFilename":"CSAgent.sys","Imphash":"4e3c3df003b6a014459f47ae8cb021c7","Authentihash":{"MD5":"d9a5aaeee6abdc6864561860f6186be7","SHA1":"2f3f30a4d24f588e458d5e36b64e58a3f28c0099","SHA256":"02576ccba2ff02ec564bef476ac55a92a16222d63c97550fb3d780f5c3de17f5"},"RichPEHeaderHash":{"MD5":"ffdf660eb1ebf020a1d0a55a90712dfb","SHA1":"3e905e3d061d0d59de61fcf39c994fcb0ec1bab3","SHA256":"2b3f99a94b7a7132854be769e27b331419c53989ef42f686d6f5ba09ddefefd6"},"Sections":{".text":{"Entropy":0,"Virtual Size":"0xf622"},".rdata":{"Entropy":0,"Virtual Size":"0xd08"},".data":{"Entropy":0,"Virtual Size":"0x308"},".pdata":{"Entropy":0,"Virtual Size":"0x540"},"INIT":{"Entropy":0,"Virtual Size":"0xd20"},".3x8":{"Entropy":0,"Virtual Size":"0x10bb45"},".8/M":{"Entropy":2.4739824188585824,"Virtual Size":"0xb0"},".lI`":{"Entropy":7.7931517364895715,"Virtual Size":"0x219f10"},".rsrc":{"Entropy":3.3910162282774605,"Virtual Size":"0x3a8"},".reloc":{"Entropy":3.3993848636069597,"Virtual Size":"0x68"}},"MagicHeader":"50 45 0 0","CreationTimestamp":"2024-11-09 09:33:54","InternalName":"CSAgent.sys","Copyright":"(c) CrowdStrike, Inc. All rights reserved.","Imports":["FLTMGR.SYS","ntoskrnl.exe","HAL.dll","ntoskrnl.exe","HAL.dll"],"ExportedFunctions":"","ImportedFunctions":["FltGetVolumeInformation","wcscat_s","HalReturnToFirmware","NtQuerySystemInformation","ExAllocatePool","IoAllocateMdl","ExFreePoolWithTag","MmProbeAndLockPages","MmMapLockedPagesSpecifyCache","MmUnlockPages","IoFreeMdl","KeQueryActiveProcessors","KeSetSystemAffinityThread","KeRevertToUserAffinityThread","DbgPrint","KeQueryPerformanceCounter"],"Signatures":[{"CertificatesInfo":"","SignerInfo":"","Certificates":[{"Subject":"C=CN, ST=Fujian, L=Fuzhou, O=Fuzhou Dingxin Trade Co., Ltd., CN=Fuzhou Dingxin Trade Co., Ltd.","ValidFrom":"2011-09-09 00:00:00","ValidTo":"2012-09-08 23:59:59","Signature":"3e2711c8787a7549ad9cb9cfa5084c7c4121368af76d17505b0f26c7f45b5ce504f5f7f7e870d5206effbd49dbccb827177ac985771d6974b72817d4f9d2ccaf8e65660f691de5e096b292ee7436bd167de254e0a587c66c4cc9f846f9c312089db032f9fbc2698c0767065a8e5bb1f3557ab75d8d34430c0f6bc3636e299287f91968eb15bede16a847c074764c56ee771e970ae2c14cd2e55bf52424d36d458dc3fb364914ea9e644e96223af33e755303864776399e71c40cc33be6f26b29fe9587ba28f2038109b901067db9718b4a3394f161a30c6b89a2c36c280cec6d6e2e14649c9af7575b25f0a251ba0e35b8c2bac1aaf2071e81fccd1e06c7bc0f","SignatureAlgorithmOID":"1.2.840.113549.1.1.5","IsCertificateAuthority":false,"SerialNumber":"72881f10cd248a33e61243a9e150ec1d","Version":3,"CertificateType":"Leaf (Code Signing)","IsCodeSigning":true,"IsCA":false,"TBS":{"MD5":"624760813f627e4fafa0b8b64ebe43f5","SHA1":"4a69bc5f9523215cdd591b21f11b6944cb0a4888","SHA256":"5d6985cb9bce20635df75b2f112bd55c961c0f144a3780283e61596dcbb25027","SHA384":"a77c2ac8e07e16e534ef036c7c7b30ba56ee47c88dc7f8c22e6fdbb234eb50a85222aa9ab24148053fec4049c4cb5fe9"}},{"Subject":"C=US, O=Thawte, Inc., CN=Thawte Code Signing CA , G2","ValidFrom":"2010-02-08 00:00:00","ValidTo":"2020-02-07 23:59:59","Signature":"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","SignatureAlgorithmOID":"1.2.840.113549.1.1.5","IsCertificateAuthority":true,"SerialNumber":"47974d7873a5bcab0d2fb370192fce5e","Version":3,"CertificateType":"CA","IsCodeSigning":true,"IsCA":true,"TBS":{"MD5":"e3a93dc2a8a8a668fdbb286bfe9afab5","SHA1":"95795d2aa2a554a423bc8c6e5b0a016d14887d35","SHA256":"d8844186775bddbccaf3dc017064df7d760fd4b85c5d07561a3efd7da950f89e","SHA384":"78d972495720b43a6470b18ae1226bcca20707628087717a9364c14ca053ba264e6d149718b103542d9942200138a69d"}},{"Subject":"C=US, O=thawte, Inc., OU=Certification Services Division, OU=(c) 2006 thawte, Inc. , For authorized use only, CN=thawte Primary Root CA","ValidFrom":"2011-02-22 19:31:57","ValidTo":"2021-02-22 19:41:57","Signature":"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","SignatureAlgorithmOID":"1.2.840.113549.1.1.5","IsCertificateAuthority":true,"SerialNumber":"611fb0a400000000001d","Version":3,"CertificateType":"CA","IsCodeSigning":false,"IsCA":true,"TBS":{"MD5":"a3f222107d4e1085e73b5b589c2f480b","SHA1":"b94aa26cd77c48d91a53ac44506cbd255e1d362c","SHA256":"a39ed0d6fd4eb1a6f7fed60f726e23eae668b7591bc004644625d22c701213fa","SHA384":"64b7643e4146016cbf83c911eb67e4601b6bb8d66f8ee8dcee67b815f91770d86ab23678b984430f22a963e5484881b7"}}],"Signer":[{"SerialNumber":"72881f10cd248a33e61243a9e150ec1d","Issuer":"C=US, O=Thawte, Inc., CN=Thawte Code Signing CA , G2","Version":1}]}]}],"Tags":["isodrivep64.sys"]}