What is OSX.Pirrit?
OSX.Pirrit is a type of adware that infects Apple Mac computers. It is part of the Pirrit advertising malware family. Adware displays intrusive advertisements and collects data about users’ browsing habits.
OSX.Pirrit specifically infects web browsers like Safari and Chrome to inject ads as users browse the web. It can modify search engine results pages and display additional ads on web pages. The adware is often bundled with free programs and installed without the user’s knowledge.
How Does OSX.Pirrit Infect Macs?
There are a few common infection methods used by OSX.Pirrit adware:
-
Bundled downloads – The adware files are bundled with free software downloads for Mac. If users fail to read disclosures and uncheck optional installs, the adware may be installed on their system without consent.
-
Misleading ads or pop-ups – Fake security alerts and other pop-up ads trick users into downloading malware under the guise of removing nonexistent infections.
-
Pirated software – Downloading cracked software from unofficial sources is risky. Pirated programs are often bundled with adware payloads.
Once installed, OSX.Pirrit inserts malicious JavaScript code into the victim’s browsers. This code injects additional advertisements into pages and hijacks browser settings.
Why is OSX.Pirrit Undetectable by Antivirus?
Most Mac antivirus software relies on signature-based detection to identify threats. This means the antivirus needs an existing signature or definition for a specific piece of malware in order to detect it.
OSX.Pirrit uses several evasion techniques to avoid creating unique signatures that security vendors can identify:
-
Code obfuscation – The malware code is scrambled and rewritten to appear different each time it infects a new system. This prevents signature matches.
-
Domain generation algorithm (DGA) – It uses an algorithm to generate new domains periodically. This prevents domain blacklisting.
-
Data encryption – Encrypted data exchanges prevent analysis of malware behaviors and payloads.
Without identifiable signatures for the antivirus to match, OSX.Pirrit remains undetectable. Mac users may not realize their systems are infected.
Signs of an OSX.Pirrit Infection
Here are some red flags indicating an OSX.Pirrit infection:
- Sudden pop-up, banner, and video ads in your browser
- Browser homepage and default search engine changed unexpectedly
- New unknown browser extensions installed without permission
- Slow browser performance
- Unknown processes running in Activity Monitor
How to Remove OSX.Pirrit Adware
If you suspect an OSX.Pirrit infection, take the following steps to remove it:
- Run an adware scan with Malwarebytes for Mac. It uses heuristic analysis to detect new threats.
- Remove any unknown extensions from your web browsers.
- Check for unknown launch agents in
/Library/LaunchAgentsand remove any suspicious files. - Reset your browser settings and remove adware from your homepage and search engine defaults.
- Update your Mac operating system and software to the latest versions.
Stay vigilant and avoid downloading questionable programs to keep OSX.Pirrit and other adware off your Mac. Use trusted antivirus software with modern detection techniques and be wary of online ads designed to mislead users.
