Suspicious Access to Web Browser Credential Stores
Description
Identifies access to more than one web browser's credential store data by the same process. Adversaries may steal credentials from web browsers by reading files specific to the target browser.
Query · eql
sequence by process.entity_id with maxspan=1m
[file where event.action == "open" and process.executable != null and
user.id : ("S-1-5-21*", "S-1-12-*") and not process.pid == 4 and process.code_signature.trusted != true and
file.path :
( /* chromium based browsers (chrome, edge, brave etc.) */
"?:\\Users\\*\\AppData\\Local\\*\\User Data\\Default\\Login Data",
/* some infostealers access only the cookies file and don't touch pwd file logins.json */
"?:\\Users\\*\\AppData\\Roaming\\Mozilla\\Firefox\\Profiles\\*default*\\logins.json",
"?:\\Users\\*\\AppData\\Roaming\\Mozilla\\Firefox\\Profiles\\*default*\\cookies.sqlite") and
not process.executable :
("?:\\Program Files\\*.exe",
"?:\\Program Files (x86)\\*.exe",
"?:\\ProgramData\\Microsoft\\Windows Defender\\Platform\\*\\MsMpEng.exe",
"?:\\Program Files\\Microsoft Security Client\\MsMpEng.exe",
"*\\Program Files*\\Windows Defender\\MsMpEng.exe" ,
"\\Device\\Mup\\*\\firefox.exe")] as event0
[file where event.action == "open" and process.executable != null and
file.path :
("?:\\Users\\*\\AppData\\Local\\*\\User Data\\Default\\Login Data",
"?:\\Users\\*\\AppData\\Roaming\\Mozilla\\Firefox\\Profiles\\*default*\\logins.json",
"?:\\Users\\*\\AppData\\Roaming\\Mozilla\\Firefox\\Profiles\\*default*\\cookies.sqlite") and
not startswith~(file.path, event0.file.path)]