The Evolving Threat of Cookie Session Hijacking: How Infostealers Enable Advanced Cyberattacks

Cyberattacks are becoming increasingly sophisticated, with cookie session hijacking emerging as a significant threat. This technique allows attackers to bypass even advanced security measures like multi-factor authentication (MFA), enabling unauthorized access to critical systems and user accounts. Infostealers, a category of malware designed to harvest sensitive information, have become a primary tool for conducting these attacks. This blog explores how infostealers facilitate cookie session hijacking, its implications for organizations, and how businesses can defend against this evolving threat

How Cookie Session Hijacking Works

Cookie session hijacking is a process in which attackers steal and reuse session cookies to impersonate authenticated users. Here’s how the attack typically unfolds:

1. Initial Infection:
   1. Attackers use infostealers, phishing emails, or other malicious techniques to compromise a user’s device.
   1. Infostealers like RedLine, Racoon, Vidar, Meta, and Lumma are commonly deployed to harvest session cookies from compromised devices.
2. Cookie Extraction:
   1. Once the device is infected, the infostealer accesses the browser’s database to extract session cookies.
   1. These cookies are stored locally on the system, typically in locations like %localappdata%\Google\Chrome\User Data\Default\Cookies.
   1. Advanced tools like Mimikatz can decrypt protected cookies.
3. Session Hijacking:
   1. Stolen cookies are imported into the attacker’s browser using tools like “Cookie Quick Manager” (Firefox) or “cookies.txt importer” (Chromium-based browsers).
   1. The attacker now gains access to authenticated user sessions without needing credentials or MFA tokens.

• Exploitation:
  • Attackers leverage hijacked sessions to gain unauthorized access to critical systems, such as cloud administration consoles, collaboration platforms, and web-based email services.

• This access can facilitate further attacks, including data exfiltration, lateral movement within networks, or ransomware deployment.

Real-World Vulnerabilities Exploited Through Cookie Session Hijacking

Cookie session hijacking poses significant risks across most of the platforms and industries, so it is not limited to niche applications. We have tested and discovered vulnerabilities in many commonly used services:

• Email Services (including corporate emails)
  • Web-based email services are one of the most critical assets attackers seek to compromise. By hijacking session cookies, threat actors can bypass traditional authentication, gaining access to email accounts without needing the user’s password or two-factor authentication codes. This access level allows attackers to monitor and even exfiltrate sensitive data, conduct spear-phishing campaigns, reset passwords for other linked services, or impersonate the victim in business correspondence. The repercussions are severe, ranging from data breaches to financial fraud, as attackers use compromised email accounts to pivot and gain access to more valuable assets.

• Collaboration and Productivity Tools
  • With the rise of remote work, collaboration platforms like Slack, Microsoft Teams, and Google Workspace have become indispensable. Unfortunately, these tools are also vulnerable to cookie hijacking. Attackers who gain access to these sessions can infiltrate internal company communications, steal sensitive documents, and even disrupt workflows. This not only compromises the integrity and confidentiality of internal discussions but can also provide attackers with insights into project timelines, corporate strategies, and employee details, setting the stage for further attacks, such as ransomware or insider threats.

• Cloud Administration Consoles
  • Perhaps the most concerning are attacks targeting cloud administration consoles. These consoles provide deep access to a company’s digital infrastructure. Hijacked sessions here allow attackers to potentially manipulate cloud resources, disrupt services, or even delete critical infrastructure. The potential damage ranges from service outages to complete data loss, making cloud environments a prime target for sophisticated threat actors.

• AI Tools like ChatGPT
  • AI tools, such as ChatGPT, have also become targets for cookie session hijacking. Attackers who hijack sessions of AI tools can impersonate users and access sensitive conversations, which may include proprietary or confidential information.

• Social Media and Messaging Platforms
  • Many popular social media and messaging platforms are particularly vulnerable to cookie-based session hijacking. These platforms often allow users to replicate sessions across devices without requiring additional validation. This convenient feature, intended for user experience, becomes a weak point for security. Attackers who gain access to session cookies can use them to impersonate victims, gaining full access to their accounts, including private messages and sensitive interactions. This form of unauthorized access can lead to identity theft, social engineering attacks, or even brand impersonation to deceive contacts.

Implications for Organizations

Once attackers successfully hijack a session, they often move quickly to exploit the compromised account. For individuals, this can mean loss of privacy, unauthorized purchases, or fraudulent messages sent to contacts. For companies, the impact can be far more devastating:

• Corporate Espionage: Access to internal communication tools can reveal sensitive business strategies and negotiations.
• Financial Fraud: Compromised email or cloud accounts can lead to unauthorized transactions or blackmail.
• Supply Chain Attacks: Attackers can use hijacked sessions to impersonate company employees and target partners or suppliers, leading to a broader compromise of the supply chain.
• Data Exfiltration: Threat actors can use hijacked accounts to extract sensitive information, which is then sold or used for further attacks.

Conclusion: The Role of Constella.ai in Combating Cookie Session Hijacking

Constella.ai offers an integrated cybersecurity solution that enables organizations to detect and mitigate threats posed by cookie session hijacking. By continuously monitoring for compromised credentials and session cookies, Constella.ai ensures early detection of vulnerabilities, preventing attackers from bypassing MFA or hijacking user sessions. Advanced attack surface mapping and real-time alerts empower organizations to address risks proactively, safeguarding critical systems and sensitive data.

As cyber threats evolve, the ability to detect and neutralize cookie session hijacking will be a cornerstone of organizational security. By implementing robust defenses and leveraging tools like Constella.ai, businesses can stay ahead of attackers, protecting both their operations and their reputation in an increasingly hostile digital landscape.