Introduction
Privilege escalation is one of the most critical steps in the cyber kill chain. Once attackers gain initial access—often through phishing, social engineering, or exploiting vulnerabilities—they typically have limited permissions. To cause real damage, move laterally, or access sensitive data, they need more power. That’s where privilege escalation comes into play.
Understanding how attackers escalate privileges helps defenders detect suspicious behavior, block techniques, and minimize the blast radius of intrusions.
What Is Privilege Escalation?
Privilege escalation occurs when a user or process gains higher-level permissions than originally intended. There are two primary types:
- Vertical privilege escalation – Gaining higher privileges (e.g., a regular user becoming admin).
- Horizontal privilege escalation – Gaining access to other users’ accounts or systems at the same privilege level.
Common Methods Used in Modern Attacks
1. Exploiting Unpatched Vulnerabilities
Attackers frequently exploit known bugs in the OS or software to execute code at a higher privilege level.
- Examples:
- Kernel exploits (e.g., CVE-2021-4034 “PwnKit”)
- Privilege escalation flaws in drivers
- Misconfigured services with weak permissions
Defense: Patch regularly, monitor CVEs, and use endpoint protection that blocks exploit behavior.
2. Abuse of Misconfigurations
Poor security configurations can offer easy privilege escalation opportunities.
- Unrestricted service permissions
- Writable system paths
- Weak file/folder permissions
- Insecure Active Directory settings
Defense: Run regular security baselines (e.g., CIS Benchmarks), and use tools like AccessChk or SharpUp to detect weak permissions.
3. Credential Dumping and Pass-the-Hash
Once on a system, attackers attempt to extract credentials from memory or disk.
- Use tools like Mimikatz to dump LSASS memory
- Pass-the-hash to authenticate using stolen NTLM hashes without knowing passwords
- Dump SAM and SYSTEM hives to extract local credentials
Defense: Enable Credential Guard, restrict admin rights, monitor LSASS access, and block known tools.
4. DLL Hijacking and Binary Planting
Attackers place malicious DLLs in locations where trusted applications will load them unknowingly.
- Exploits applications that search for DLLs in insecure directories
- Used to execute malicious code under the context of the application
Defense: Use application whitelisting (e.g., AppLocker), monitor file paths, and restrict write permissions on system folders.
5. Scheduled Tasks and Services Abuse
Attackers create or modify scheduled tasks or services to execute code as SYSTEM or other privileged users.
- Create persistent backdoors
- Trigger malicious payloads after reboot or at set times
Defense: Monitor new scheduled tasks and service creations with tools like Sysmon and EDR solutions.
6. Token Impersonation
Attackers steal or impersonate security tokens to execute actions as a privileged user.
- Primary token theft from SYSTEM processes
- Kerberos ticket theft (“Pass-the-Ticket”) to access other systems
Defense: Monitor token usage, implement least privilege, and use managed identities.
How to Detect and Prevent Privilege Escalation
- Least Privilege Access – Don’t grant more access than needed
- Segmentation – Limit the impact of a compromised user or system
- Auditing and Monitoring – Set alerts for privilege changes and suspicious behaviors
- EDR/XDR Solutions – Use behavioral detection to flag unusual activities
- Regular Penetration Testing – Simulate attacks to find weak points before attackers do
Conclusion
Privilege escalation is a cornerstone of modern attacks. It turns a minor intrusion into a major compromise. By understanding the techniques used by attackers—and applying layered, proactive defense strategies—organizations can prevent small mistakes from becoming major incidents.
Need help evaluating your environment for privilege escalation risks? Talk to our team — we specialize in identifying misconfigurations and securing your most critical assets.