Cookie-Bite and Session Hijacking: How Cybercriminals Bypass Passwords
Neil Hare-Brown- Apr 28
- 2 min read
Updated: 1 day ago
Passwords aren’t the only thing cybercriminals want anymore. Increasingly, attackers are targeting browser session tokens — stealing active sessions to slip past authentication entirely.
One emerging method is the Cookie-Bite attack: a proof-of-concept that shows how a simple browser extension could give attackers access to your business email, cloud platforms, financial portals, and more — without needing your password or triggering MFA.
Here’s everything you need to know about Cookie-Bite, how it works, and how to defend against it.
What Is Cookie-Bite?
Cookie-Bite refers to a proof-of-concept attack where a malicious Chrome extension steals browser session tokens from a victim’s computer.
Session tokens are what keep you logged into websites after authentication. If stolen, they allow an attacker to hijack that session — impersonating you on services like:
Microsoft 365
Google Workspace
Dropbox
Salesforce
Amazon Web Services (AWS)
Banking and payment portals
Importantly:
No password needed
MFA protections often bypassed
No immediate login alerts triggered
Attackers using Cookie-Bite don’t need to phish your login — they quietly piggyback your trusted session instead.
How Cookie-Bite Attacks Work (Step-by-Step)
Victim installs a malicious Chrome extension
The extension quietly accesses Chrome’s local storage
Session tokens for major services are extracted Such as:
__Host-3PLSID (Google)
SAMLAuthToken (SAML-based apps)
MSISAuth (Microsoft login sessions)
Tokens are exfiltrated to the attacker's server
Attacker imports tokens into their own browser
Attacker accesses business services without triggering alerts
What Cyber Attacks Can Follow Session Theft?
Session hijacking through techniques like Cookie-Bite can open the door to a wide range of attacks, including:
Business Email Compromise (BEC)
Internal Reconnaissance and Cloud Breach
Credential Dumping and Privilege Escalation
Data Exfiltration and Sale
Ransomware Deployment
Learn more about the types of cyber incidents your business could face.
Cookie-Bite isn’t the final attack — it’s the way in.
Why Cookie-Bite Is So Dangerous
✅ Bypasses passwords — no matter how strong they are
✅ Often bypasses MFA — hijacking happens post-authentication
✅ Hard to detect — sessions look legitimate to systems
✅ Works across many apps — not just email or cloud storage
✅ Easy to deliver — browser extensions are easy to disguise
How to Defend Against Cookie-Bite and Session Hijacking
✅ Limit Browser Extensions to only approved, vetted ones
✅ Monitor Chrome and Browser Behaviour using EDR/XDR
✅ Shorten Session Lifetimes to limit stolen session usability
✅ Use Conditional Access to enforce trust checks
✅ Prompt Reauthentication for Sensitive Actions
✅ Educate Staff on extension risks and session hijacking threats
Need help strengthening your endpoint and session security? Explore our cyber incident response services.
What to Watch for: Indicators of Cookie-Bite-Type Activity
Unapproved Chrome extensions installed across devices
Logins without normal authentication flows
Sessions lasting far beyond normal timeouts
Access from strange IPs without password re-entry
Missing login alerts where MFA would normally trigger
How STORM Guidance Can Help
✔ Endpoint and browser security reviews
✔ Threat intelligence monitoring for credential and session theft
✔ Cyber incident response if session hijacking is detected
✔ Threat actor engagement for follow-on ransomware or extortion attempts
Stay Ahead of Emerging Cyber Threats
Attacks like Cookie-Bite show that cybercriminals aren’t just after your passwords — they’re after your trusted sessions, too.
Protecting your business requires proactive defence, staff awareness, and quick response if something feels wrong.
For broader support, explore Storm Guidance's threat intelligence and cyber risk services.
