Steal Web Session Cookie

Steal Web Session Cookie [T1539]

Information

• Name: Steal Web Session Cookie

• ID: T1539

• Tactics: TA0006

Introduction

Stealing web session cookies is categorized under the MITRE ATT&CK framework as technique T1539 - Steal Web Session Cookie, part of the Credential Access tactic. Attackers target session cookies to hijack authenticated user sessions, bypassing traditional login mechanisms. Session cookies are valuable as they allow attackers to impersonate legitimate users, maintain persistent access, and escalate privileges without needing the user's credentials directly.

Deep Dive Into Technique

Session cookies are small pieces of data stored in a user's browser, uniquely identifying an authenticated session with a web application. Attackers steal these cookies to gain unauthorized access to applications without needing usernames or passwords.

Technical execution methods include:

• Cross-Site Scripting (XSS):

  • Inject malicious JavaScript code into vulnerable web pages.

  • Capture session cookies from victim browsers and send them to attacker-controlled servers.

• Man-in-the-Middle (MitM) Attacks:

  • Intercept HTTP traffic between user and web application.

  • Extract session cookies transmitted in cleartext or weakly encrypted channels.

• Malicious Browser Extensions or Malware:

  • Install malware or compromised extensions on victim devices.

  • Directly access stored cookies from browser databases or memory.

• Network Sniffing:

  • Monitor unsecured Wi-Fi networks or compromised internal networks.

  • Capture unencrypted or weakly encrypted cookies transmitted over HTTP.

Real-world procedures often involve:

• Automated scripts to harvest session cookies from compromised browsers.

• Immediate reuse of stolen cookies to hijack sessions before expiration or invalidation.

• Leveraging stolen sessions to pivot deeper into targeted networks or escalate privileges.

When this Technique is Usually Used

Attackers commonly utilize session cookie theft during multiple stages and scenarios, including:

• Initial Access and Reconnaissance:

  • Early-stage attacks aiming to gain initial footholds within web-based applications.

  • Capturing session cookies from public Wi-Fi or vulnerable web applications.

• Persistence and Session Hijacking:

  • Maintaining persistent access to victim accounts without repeated credential theft.

  • Repeatedly accessing sensitive information over an extended period.

• Privilege Escalation and Lateral Movement:

  • Using stolen sessions from privileged users to escalate privileges.

  • Pivoting to other internal systems and applications accessible via compromised accounts.

• Targeted Attacks and Espionage:

  • APT groups targeting high-value individuals or organizations.

  • Espionage operations aiming at sensitive corporate or governmental data.

How this Technique is Usually Detected

Detection methods include:

• Monitoring for Suspicious Session Activity:

  • Unusual geographic locations or IP addresses accessing user sessions.

  • Rapid session reuse from different locations or devices.

• Analyzing HTTP Traffic:

  • Detecting cookie theft through Intrusion Detection Systems (IDS) or Web Application Firewalls (WAF).

  • Identifying anomalous HTTP requests or unusual cookie headers.

• Endpoint Security Solutions:

  • Endpoint Detection and Response (EDR) tools detecting malware or malicious browser extensions accessing cookie stores.

  • Security software identifying unauthorized access to browser databases.

• Behavioral Analysis and Anomaly Detection:

  • User and Entity Behavior Analytics (UEBA) tools identifying abnormal user session patterns.

  • Detection of simultaneous sessions or impossible travel scenarios.

Indicators of Compromise (IoCs) include:

• Sudden logins from unexpected locations or IP addresses.

• User sessions active from multiple locations simultaneously.

• Malicious JavaScript code detected in web application logs.

• Suspicious browser extensions or malware identified in endpoint security alerts.

• HTTP requests to attacker-controlled domains or IP addresses.

Why it is Important to Detect This Technique

Early detection of web session cookie theft is crucial due to significant impacts:

• Unauthorized Access and Data Breaches:

  • Attackers gain immediate access to sensitive personal, financial, or corporate data without requiring credentials.

• Persistence and Long-Term Compromise:

  • Attackers maintain persistent access, potentially going unnoticed for extended periods.

  • Persistent sessions allow continuous exfiltration of sensitive data.

• Reputation Damage and Compliance Issues:

  • Compromise of customer or employee data leads to severe reputational damage.

  • Regulatory compliance violations (GDPR, HIPAA) resulting in financial penalties.

• Potential Lateral Movement and Privilege Escalation:

  • Stolen sessions provide attackers with opportunities to escalate privileges and move laterally within networks.

  • Increased likelihood of significant breaches and operational disruptions.

Early detection allows organizations to:

• Quickly invalidate compromised sessions.

• Mitigate further damage by isolating affected systems and accounts.

• Strengthen defenses and remediate vulnerabilities exploited during the attack.

Examples

Real-world examples of session cookie theft include:

• Magecart Attacks:

  • Attackers injected malicious JavaScript into e-commerce websites, stealing session cookies and payment card information.

  • Impact: Large-scale data breaches affecting thousands of customers, significant financial and reputational damage.

• Operation Aurora (Google Attack, 2010):

  • Attackers leveraged stolen session cookies to compromise Gmail accounts of targeted individuals.

  • Technique: Exploited vulnerabilities to extract session cookies, bypassing authentication.

  • Impact: Unauthorized access to sensitive emails and data, prompting Google to enhance security measures.

• Firesheep Tool (2010):

  • Publicly available tool demonstrating ease of session cookie theft on unsecured Wi-Fi networks.

  • Technique: Network sniffing and cookie capture from unencrypted HTTP sessions.

  • Impact: Raised awareness about risks of unsecured HTTP sessions, leading to widespread adoption of HTTPS.

• APT29 (Cozy Bear) Espionage Campaigns:

  • Russian-linked threat actors used session cookie theft to maintain persistent access to targeted government and corporate networks.

  • Technique: Malware and phishing attacks to steal browser-stored cookies.

  • Impact: Long-term espionage operations, significant data exfiltration, and national security implications.