How to remove Poseidon Stealer (Mac)

What is Poseidon Stealer

Poseidon Stealer is a sophisticated piece of malware designed primarily to infiltrate macOS systems and exfiltrate sensitive information such as passwords, credit card details, and personal documents. This malicious software operates silently in the background, making it difficult for users to detect its presence until significant damage has been done. Once installed, it can intercept web traffic, log keystrokes, and even access stored credentials from browsers and other applications. The consequences of a Poseidon Stealer infection can be severe, leading to identity theft, financial loss, and unauthorized access to personal and corporate accounts. Additionally, the malware often opens backdoors, allowing cybercriminals to install other malicious payloads or gain persistent access to the infected system. Users may notice unusual system behavior, such as slow performance or unexpected pop-ups, which can be indicators of this stealthy threat. Prompt detection and removal are crucial to mitigating the risks associated with this potent stealer.

How Poseidon Stealer infected your system

Poseidon Stealer is a sophisticated piece of malware that primarily targets macOS systems to exfiltrate sensitive data. This malicious software often infiltrates computers through deceptive methods such as phishing emails, malicious attachments, or compromised websites that exploit browser vulnerabilities. Once executed, Poseidon Stealer operates stealthily in the background, avoiding detection by employing various evasion techniques. It typically takes advantage of system flaws or user carelessness to install itself without raising alarms. After establishing a foothold, it begins to gather sensitive information, including passwords, financial data, and personal files, sending them back to a remote command and control server operated by cybercriminals. Users can mitigate the risk of infection by maintaining up-to-date security software, exercising caution with unsolicited emails, and regularly updating their operating systems and applications.

Remove Poseidon Stealer from macOS manually

Removing Poseidon Stealer from macOS requires a systematic approach that involves a combination of built-in tools, safe computing practices, and sometimes third-party software. Here’s a comprehensive guide to identifying and removing viruses from your Mac, ensuring your system’s integrity and security.

Step 1: Disconnect from the Internet

1. Disconnect your Mac from the Internet. This prevents the virus from sending data to its creator or downloading more malicious software. Turn off Wi-Fi and unplug any Ethernet cables.

Step 2: Enter Safe Mode

2. Restart your Mac in Safe Mode. Safe Mode performs a check of your startup disk and restricts certain software from automatically loading or opening.
   • For Intel-based Macs: Restart your Mac and immediately press and hold the Shift key until you see the login window.
   • For Apple Silicon Macs: Turn off your Mac, press and hold the power button until you see the startup options window, select your startup disk, press and hold the Shift key, then click Continue in Safe Mode.

Step 3: Use Built-in Tools for Malware Removal

3. Use Finder to identify and remove suspicious applications.
   • Open Finder, go to the Applications folder, and look for any applications you don’t recognize or didn’t intentionally download.
   • Right-click the suspicious application and select Move to Trash, then empty the Trash.
4. Use macOS built-in malware removal tool (MRT). macOS automatically runs MRT in the background, but you can manually run a malware scan by updating your software.
   • Go to System Preferences > Software Update.
   • Install any available updates, as these often include the latest security improvements and malware definitions.

Step 4: Check and remove Poseidon Stealer from Login Items

Note: Poseidon Stealer may set up to start on macOS startup. Therefore, before starting the removal, perform these steps:

1. Open System Preferences, choose Users & Groups.
2. Choose your account (set up as Current User).
3. Click Login Items tab.
4. Find suspicious entries. Select it, and click the “-“ (minus) button to remove them.

Step 5: Check and remove Poseidon Stealer Malicious Device Profile

Important update: Poseidon Stealer can install malicious Device Profile called AdminPrefs or similarly on MacOS, that won’t allow users to make changes to browser search engine and homepage settings. Follow instructions below to remove this profile.

Remove Poseidon Stealer profile

1. Go to System Preferences and click on Profiles.
2. In the list of profiles on the left side, choose AdminPrefs or other profile and click on “-” button to remove it.
3. In your case it can be named differently, in this case remove all visible profiles. Check the picture below to see how it looks like.

Step 6: Reset Your Web Browsers

Reset Safari:

1. Start Safari on your Mac, click Safari to open drop-down menu and choose Preferences
2. Go to the Privacy section of Safari’s preferences.
3. Click Remove All Website Data button.
4. In the opened window, click Remove Now button to remove data stored by websites in Safari.
5. Go to the Advanced section of Safari’s preferences.
6. Click the Show Develop menu in menu bar option.
7. In the menu, click Develop and select Empty Caches from this menu.
8. Again, go to Safari menu and choose Clear History….
9. Choose to clear all history and click Clear History button.

Reset Google Chrome:

1. Start Google Chrome browser
2. In address box type (or copy-paste) chrome://settings.
3. Scroll down and find Show advanced settings link.
4. Click on it and scroll down to the bottom again.
5. Click Reset settings button and click Reset to confirm.

Reset Mozilla Firefox:

1. Start Mozilla Firefox browser.
2. In address box type (or copy-paste) about:support.
3. Click Refresh Firefox… button.
4. Click Refresh Firefox to confirm.

Step 7: Restore from a Backup

8. If the issue persists, consider restoring your Mac from a backup.
   • Use Time Machine or another backup system to restore your Mac to a state before it was infected.
   • Ensure the backup you choose predates the malware infection.

Prevention Tips

• Keep your macOS updated. Regularly check for and install macOS updates to ensure you have the latest security patches.
• Be cautious with downloads and attachments. Only download software from trusted sources like the Mac App Store or official websites.
• Use strong passwords and enable two-factor authentication (2FA) where possible.
• Consider enabling the macOS firewall in System Preferences > Security & Privacy.
• Regularly back up your Mac using Time Machine or another backup solution to ensure you can recover your system if needed.

Following these steps should help you remove most viruses from your Mac. If you continue to experience issues, consider seeking help from Apple Support or a professional cybersecurity service.