Detect Browser Session Hijacking in Google Chronicle
Adversaries may take advantage of security vulnerabilities and inherent functionality in browser software to change content, modify user behaviors, and intercept information as part of various browser session hijacking techniques. A specific example is when an adversary injects software into a browser process that allows them to inherit cookies, HTTP sessions, and SSL client certificates of a user, then uses the browser as a pivot into an authenticated intranet. Executing browser-based behaviors such as pivoting may require specific process permissions, such as SeDebugPrivilege and/or high-integrity/administrator rights. Another technique involves redirecting browser traffic through an adversary-controlled proxy injected into the browser process, allowing session impersonation without modifying user-visible traffic. Malware families such as TrickBot, Dridex, IcedID, QakBot, and Cobalt Strike implement browser pivoting and web inject techniques to steal banking credentials, session tokens, and SSL certificates.
MITRE ATT&CK
- Tactic
- Collection
- Technique
- T1185 Browser Session Hijacking
- Canonical reference
- https://attack.mitre.org/techniques/T1185/
YARA-L Detection Query
rule t1185_browser_session_hijacking {
meta:
author = "Argus Detection Engineering"
description = "Detects browser session hijacking via process injection or DLL load into browser processes"
mitre_attack_tactic = "Collection"
mitre_attack_technique = "T1185"
severity = "HIGH"
priority = "HIGH"
events:
// Detection 1: CreateRemoteThread into browser
$inject.metadata.event_type = "PROCESS_INJECTION"
$inject.target.process.file.full_path = /(?i)(chrome|msedge|firefox|iexplore|brave|opera|microsoftedge)\.exe$/
not $inject.principal.process.file.full_path = /(?i)(chrome|msedge|firefox|MsMpEng|WerFault|csrss|dwm|taskmgr)\.exe$/
$inject.principal.hostname = $host
OR
// Detection 2: Suspicious library load inside browser process
$load.metadata.event_type = "PROCESS_MODULE_LOAD"
$load.principal.process.file.full_path = /(?i)(chrome|msedge|firefox|iexplore|brave|opera)\.exe$/
not $load.target.file.full_path = /(?i)(Program Files\\(Google\\Chrome|Mozilla Firefox|Microsoft\\Edge)|Windows\\(System32|SysWOW64|WinSxS))/
not $load.target.file.full_path = /(?i)(d3d|opengl|vulkan|nvidia|amd|intel)/
$load.principal.hostname = $host
condition:
$inject or $load
}Chronicle YARA-L 2.0 rule detecting browser session hijacking through two complementary patterns: process injection events targeting browser executables from non-whitelisted injectors, and suspicious DLL/module loads inside browser processes from outside standard browser installation paths. Uses UDM event types PROCESS_INJECTION and PROCESS_MODULE_LOAD.
Data Sources
Required Tables
False Positives & Tuning
- Legitimate security software accessing browser processes for scanning or monitoring
- Browser developer extensions that load DLLs from custom installation paths
- Third-party password managers or accessibility tools with browser integration
- Automated testing frameworks using browser instrumentation APIs
- Update managers or software distribution agents that access browser processes
Other platforms for T1185
Testing Methodology
Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1Browser Process Enumeration and Handle Open (ReadVM Access)
Expected signal: Sysmon EventCode=10 (ProcessAccess): SourceImage=powershell.exe, TargetImage=<browser>.exe, GrantedAccess=0x10 (PROCESS_VM_READ), CallTrace will show the kernel32.dll and ntdll.dll call stack. MDE DeviceEvents ActionType=OpenProcessApiCall with FileName=<browser>.exe, InitiatingProcessFileName=powershell.exe.
- Test 2Chrome Cookie Database Exfiltration via File Copy
Expected signal: Sysmon EventCode=11 (FileCreate): TargetFilename=%TEMP%\argus_test_cookies_*.db, Image=powershell.exe. Sysmon EventCode=1 (ProcessCreate): powershell.exe with command line referencing LOCALAPPDATA\Google\Chrome\User Data. MDE DeviceFileEvents with ActionType=FileCreated, FileName=argus_test_cookies_*.db, InitiatingProcessFileName=powershell.exe.
- Test 3Browser Proxy Configuration via Registry (Browser Pivot Simulation)
Expected signal: Sysmon EventCode=13 (RegistryValueSet): TargetObject=HKCU\Software\Microsoft\Windows\CurrentVersion\Internet Settings\ProxyServer, Details=127.0.0.1:4444, Image=powershell.exe. Second EventCode=13 for ProxyEnable=1. MDE DeviceRegistryEvents with ActionType=RegistryValueSet, RegistryValueName=ProxyServer, RegistryValueData=127.0.0.1:4444.
- Test 4CreateRemoteThread Simulation into Browser Process (Benign Payload)
Expected signal: Sysmon EventCode=8 (CreateRemoteThread): SourceImage=powershell.exe, TargetImage=<browser>.exe, StartAddress=<kernel32!Sleep address>, StartModule=C:\Windows\System32\kernel32.dll, StartFunction=Sleep. MDE DeviceEvents ActionType=CreateRemoteThreadApiCall, FileName=<browser>.exe, InitiatingProcessFileName=powershell.exe. Security Event ID 4688 for the PowerShell process if command line auditing is enabled.
References (10)
- https://attack.mitre.org/techniques/T1185/
- https://en.wikipedia.org/wiki/Man-in-the-browser
- https://www.cobaltstrike.com/help-browser-pivoting
- https://web.archive.org/web/20210825130434/https://cobaltstrike.com/downloads/csmanual38.pdf
- https://www.icebrg.io/blog/malicious-chrome-extensions-enable-criminals-to-impact-over-half-a-million-users-and-global-businesses
- https://www.fidelissecurity.com/threatgeek/threat-intelligence/trickbot-we-missed-you-dyre/
- https://securityintelligence.com/trickbot-new-banking-trojan-delivers-credential-stealing-attacks/
- https://learn.microsoft.com/en-us/defender-endpoint/advanced-hunting-deviceevents-table
- https://learn.microsoft.com/en-us/sysinternals/downloads/sysmon
- https://github.com/redcanaryco/atomic-red-team/blob/master/atomics/T1185/T1185.md
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