Elastic Defend high stable eql

Web Browser Credential Access via Unsigned Process

Identifies an unsigned process accessing the password store of commonly used web browsers. Adversaries may steal credentials from web browsers by reading files specific to the target browser.

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Detection Logic

sequence by process.entity_id with maxspan=5m
  [process where event.action == "start" and process.hash.sha256 != null and
   (
    (process.Ext.device.product_id : ("Virtual DVD-ROM", "Virtual Disk") and not process.executable : "C:\\*") or

    (process.Ext.relative_file_creation_time <= 500 and
     (process.code_signature.trusted == false or process.code_signature.exists == false) and
     not process.code_signature.status : "errorCode_endpoint*" and
     not (process.code_signature.subject_name == "Rapid7 LLC" and process.code_signature.status == "errorBadDigest"))
    ) and
    not (process.code_signature.subject_name == "Guardicore Ltd" and process.code_signature.status == "errorExpired") and
    not process.hash.sha256 : ("589c5f680eefb085a3c67c8115febbfb134dcd61e43acda83d8a2cc9c4eee035",
                               "67435999749d9e6908a4029321c0c6f9e915135e98e01a7e499a1c55a960bc68",
                               "2ef4b2d23912e15a1b0a47e17e249a909df5d973381c93741a6adbf119182e3d",
                               "6d167aee7013d61b0832937773cd71d77493a05d6ffb1849bdfb1477622e54c2",
                               "8ab494be664d7bb9a7e0dda2bc4fc6592ab26f6bb5d44b6b71b80297a532a517",
                               "eeae738673b6d694c0669fb8cd4c498b7ec6af2239d0ce3e2e6370fe75c2a771",
                               "1ea6c21fb667401513fc8c2106523510f77647a271be4f9cc1abc5b06d0e3eb5",
                               "5094013ae4283c70eeea7e2b1b4f2c084439ea8cc538473273586cf80dd79caf",
                               "84618d4ac2894c5febaf545f24285fe75cd8b4e166d5bde923661ca0d0fb7c4c")
    ]
  [file where event.type == "access" and
    /* domain user RID */
    user.id : ("S-1-5-21*", "S-1-12-*") and
    not process.executable : ("?:\\Program Files\\*.exe", "?:\\Program Files (x86)\\*.exe") and
    (
     file.name : ("logins.json", "cert?.db", "key?.db", "signons.sqlite", "cookies.sqlite") or 
     file.path : 
           ("?:\\Users\\*\\AppData\\Local\\Google\\Chrome\\User Data\\Local State",
            "?:\\Users\\*\\AppData\\Local\\Microsoft\\Edge\\User Data\\Local State", 
            "?:\\users\\*\\AppData\\Local\\Google\\Chrome\\User Data\\Default\\Login Data", 
            "?:\\Users\\*\\AppData\\Local\\Microsoft\\Edge\\User Data\\Default\\Login Data")
     ) 
     and not (process.name : "certutil.exe" and file.name : ("key?.db", "cert?.db"))
    ]

Field Validations

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