How to remove Shlayer malware from the operating system

What is Shlayer?

Shlayer is a trojan-type virus designed to proliferate various adware and other unwanted applications, and promote fake search engines. It is typically disguised as a Adobe Flash Player installer and various software cracking tools.

In most cases, users encounter this virus when visiting dubious Torrent websites that are full of intrusive advertisements and deceptive downloads.

More about Shlayer

Using Torrent and other deceptive sites as a malware distribution channel is very common amongst cyber criminals. These people present viruses as legitimate software, thereby tricking users into running malicious executables. Shlayer is one of these viruses and is designed to promote adware, unwanted applications, and fake search engines.

Shlayer typically promotes the following products: Chumsearch Safari web browser extension (which assigns certain browser settings to chumsearch.com and prevents users from reverting these changes); MyShopCoupon and mediaDownloader adware; Advanced Mac Cleaner, Mac Cleanup Pro, and; MyMacUpdater unwanted applications.

As with the Chumsearch extension, Shlayer is also designed to assign installed browsers (these viruses usually target Safari, Google Chrome, and Mozilla Firefox) new tab URL, default search engine, and homepage options to chumsearch.com, weknow.ac, or search-operator.com.

Furthermore, many other potentially unwanted applications are based on the aforementioned Advanced Mac Cleaner (e.g., Mac Speedup Pro, Mac Tweak, MacRapidizer, Mac-Mechanic, and many others). All are developed by the same criminals. Therefore, Shlayer might also be used to promote these rogue apps.

In any case, Shlayer might cause various issues. Adware-type applications deliver intrusive advertisements that lead to malicious websites and execute scripts designed to download/install malware. Thus, even a single accidental click might result in high-risk system infections.

Furthermore, adware and fake search engines record user-system information relating to browsing activity. The list of collected data types usually includes (but is not limited to) IP addresses, website URLs visited, pages viewed, search queries, and geo-locations. Collected information usually includes personal details that are shared with third parties (potentially, cyber criminals).

These people generate revenue by misusing private data. Therefore, information tracking can lead to serious privacy issues or even identity theft. In some cases, fake search engines feed users with misleading results that can also lead to malicious sites. Thus, having unwanted applications such as Advanced Mac Cleaner installed can lead to financial loss.

These applications typically perform fake system scans and display false results that contain long lists of viruses and issues that must supposedly be removed/resolved immediately.

The 'free' versions of these apps do not have this capability and users are encouraged to purchase 'advanced' versions. These applications deliver no real value and they simply clean a false list of issues.

Recognizing Shlayer

Distinguishing Shlayer is simple, since is distributed using dubious websites. Furthermore, its installer typically contains various unwanted applications/fake search engines hidden within "Custom/Advanced" settings. Once installation starts, Shlayer delivers a pop-up window asking for permission to change browser settings.

To grant these permissions, users must enter their login details and passwords. Some Shlayer variants display a full-screen installation window, which cannot be moved, minimized, or closed. This is done to prevent users from force-quitting the installation if they deem it suspicious.

In addition, installation of unwanted applications typically leaves various traces (new files and entries in various directories). You can find a list of trace examples below.

In summary, Shlayer is not sophisticated malware and its presence is easy to identify. High-end viruses do not have user-friendly interfaces allowing users to decide whether to install software - they typically work in the background, without users' consent.

How did Shlayer infiltrate my computer?

As mentioned above, many of Shlayer's samples are distributed using Torrent websites. Cyber criminals present malicious Adobe Flash Player installers and software cracks as legitimate, when in fact users end up running Shlayer. In some cases, Shlayer samples are disguised as Adobe Flash Player installers/updaters and promoted using fake-error displaying websites.

These sites deliver deceptive messages claiming that the user's Adobe Flash Player is missing or outdated, and encourages them to immediately install/update it. Note that lack of knowledge of these threats and careless behavior typically lead to Shlayer infection. For example, users who run various files downloaded from dubious sources are at most risk.

How to avoid installation of unwanted applications?

To prevent these computer infections, be very cautious when browsing the internet and downloading, installing, and updating software. Remember that intrusive advertisements typically seem legitimate. Once clicked, however, they redirect to dubious websites, such as gambling, adult dating, pornography, and similar.

If you encounter any of these ads/redirects, immediately remove all suspicious applications and browser plug-ins. Furthermore, download software from official sources only, using direct download links. Third party downloaders/installers are often used to promote rogue apps, and thus this software should never be used. The same rule applies to software updates.

Keep installed programs up-to-date, however, this should be achieved through implemented functions or tools provided by the official developer. Having a reputable anti-virus/anti-spyware suite installed and running is also paramount, since these tools can detect and eliminate malware before it does any harm.

The key to computer safety is caution. If your computer is already infected with unwanted apps, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate them.

Appearance of rogue Shlayer installation setup promoting weknow.ac and Mac Cleanup Pro (GIF):

Another variant of Shlayer installer setup promoting search-operator.com:

List of files/entries created by some variants of Shlayer trojan:

• /Applications/Advanced Mac Cleaner
• /Applications/MyMacUpdater
• /Applications/MyShopcoupon
• /Applications/mediaDownloader
• /Library/LaunchAgents/com.MyMacUpdater.agent.plist
• /Library/LaunchAgents/com.MyShopcoupon.agent.plist
• /mm-plugin.dylib
• /myshopcoupon.safariextz
• ~ Library/Application Support/amc
• ~ Library/Caches/com.apple.Safari/Extensions/Chumsearch+.safariextension
• ~ Library/LaunchAgents/com.pcv.hlpramcn.plist
• ~ Library/Safari/Extensions/Chumsearch+.safariextz

IMPORTANT NOTE! Shlayer is designed to create a new device profile. Therefore, before taking any further removal steps, perform these actions:
1) Click the "Preferences" icon in the menu bar and select "Profiles".

2) Select the "AdminPrefs" profile and delete it.

3) Perform a full system scan with Combo Cleaner anti-virus suite.

After performing these actions, you can proceed with further removal steps.

Update January 23, 2020 - Although it has been few years since the release of Shlayer trojan, it still remains extremely active in the MacOS malware field. In fact, Shlayer is the most commonly detected malware in MacOS and it is responsible for around 30% of the occurring infiltrations of adware and potentially unwanted applications.

Research also shows that Shlayer is related to a number of adware families (including Pirrit, Bundlore, Cimpli and Geonei), which are also extremely popular. In other words, Shlayer trojan is responsible for a huge proportion of MacOS infections relating to adware and potentially unwanted applications.

It is also worth noting that developers of Shlayer offer this trojan as a monetization tool for various websites. They do so by using file partner programs, which basically offer a per-installation fee for each "partner".

The "partners" have to promote the Shlayer's installer (which, as research results show, is typically disguised as a Flash Player installer/updater) and they get paid for each installation. However, it is noteworthy that developers only count installations within United States, meaning that "partner" does not get paid if the installation occurs in any other country.

Update February 8, 2023 - The Shlayer malware has a unique way of encrypting its configuration using AES within the DMG file header, which results in a modified DMG file. The modification is subtle and does not affect the functionality of the DMG file. In fact, macOS can mount and run these modified DMG files without any issues.

This recent discovery of Shlayer hiding its configuration in DMG files raises concerns about the potential for other Mac malware authors to adopt this technique for concealing crucial malware elements.

Instant automatic malware removal:

Manual threat removal might be a lengthy and complicated process that requires advanced IT skills. Combo Cleaner is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:

By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. To use full-featured product, you have to purchase a license for Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by RCS LT, the parent company of PCRisk.com.

Quick menu:

• What is Shlayer?
• STEP 1. Remove adware related files and folders from OSX.
• STEP 2. Remove rogue extensions and redirects from Safari.
• STEP 3. Remove rogue add-ons and redirects from Google Chrome.
• STEP 4. Remove potentially unwanted plug-ins and redirects from Mozilla Firefox.

Video showing how to remove Shlayer trojan using Combo Cleaner:

Unwanted applications removal:

Remove potentially unwanted applications from your "Applications" folder:

Click the Finder icon. In the Finder window, select "Applications". In the applications folder, look for "MPlayerX","NicePlayer", or other suspicious applications and drag them to the Trash. After removing the potentially unwanted application(s) that cause online ads, scan your Mac for any remaining unwanted components.

Malware removal:

If unfamiliar processes are running, browser searches are being redirected, fans are spinning loudly for no reason, or fake "Update Safari" prompts have appeared, your Mac is likely infected. Run a full scan with Combo Cleaner for Mac to remove the infection. The full manual procedure below covers cases where automatic removal failed, where you want to verify a scan caught everything, or where the malware has multiple persistence points across LaunchAgents, LaunchDaemons, and Configuration Profiles.

Common Mac malware behaviors

VisibleAdware injection - browser hijackers and fake search engines

The most common Mac malware. Replaces your default search engine, homepage, or new-tab page with a lookalike domain that funnels every query through ad networks before passing it to a real provider. Often arrives bundled with cracked apps, fake Flash Player updates, or "free media player" downloads (MPlayerX, NicePlayer).

HiddenLaunchAgent / LaunchDaemon persistence

The standard way Mac malware survives reboots. A small .plist file in /Library/LaunchAgents/, /Library/LaunchDaemons/, or ~/Library/LaunchAgents/ tells launchd to run the malware at every login or boot. The .plist often picks a generic-looking name like com.apple.AdobeFlash.plist or com.system.helper.plist to blend in among legitimate Apple files.

HiddenConfiguration Profile abuse

Configuration Profiles are an enterprise feature - they let an IT department enforce policy on managed Macs (homepage, DNS, certificates, password rules). Adware abuses this by silently installing a Profile that locks the browser homepage, default search, or DNS server at the OS level. Manual browser reset doesn't help - the Profile reapplies the hijack. Check System Settings → General → Device Management (or "Profiles" on older macOS).

VisibleFake update prompts (FlashPlayer.dmg variants)

"Your Flash Player is out of date" or "Update your browser to view this content." Adobe killed Flash in 2020 - any current "Flash update" prompt is malware. The Atomic macOS Stealer (AMOS) family heavily uses this trick to deliver info-stealers that grab browser passwords, keychain items, and crypto wallet seed phrases. Apple's Software Update never appears as a browser pop-up.

SymptomCryptominer CPU usage

Fans spin loudly, the Mac runs hot, battery drains fast, Activity Monitor shows a process near 100% CPU. Cryptominers run silently in the background to mint cryptocurrency for the attacker. Often delivered via cracked apps from torrent sites, browser extensions, or supply-chain compromises in legitimate Mac software.

HiddenInfo stealing - AMOS, Banshee, Cthulhu, RustDoor

Modern Mac stealer families - AMOS (Atomic macOS Stealer), Banshee, Cthulhu, and RustDoor are the most active - read browser-saved passwords, cookies, autofill data, the macOS Keychain, crypto wallet seed phrases (Exodus, Electrum, Trezor Suite, MetaMask, etc.), and Apple Notes. AMOS is the most prolific overall, distributed via fake software installers, cracked apps, and fake "Spotlight" or "ChatGPT" sites. Once data is exfiltrated, the malware often deletes itself, leaving little trace - which is why credential rotation in Step 10 is critical even after the infection appears gone.

Tools you'll need

Combo Cleaner for Mac 7-days free trial available

Recommended primary scanner. Detects adware, info-stealers, cryptominers, and the persistence files they install.

Activity Monitor Free · built-in

Built into macOS. Shows running processes with full file paths, CPU, memory, and network usage.

KnockKnock Free

By Objective-See (Patrick Wardle). Lists every place macOS malware can persist - LaunchAgents, LaunchDaemons, Login Items, Cron, Browser Extensions, Kernel Extensions, more.

Console.app Free · built-in

Built into macOS (Applications → Utilities). Shows system logs - useful for finding what process is launching a suspicious child.

Contain - limit the damage

~5 min

1

Disconnect from the network

⏱ 30 secNo tool needed

Click the Wi-Fi icon in the menu bar (or open Control Center) and turn Wi-Fi off. If you're on Ethernet, unplug the cable. This stops any active info-stealer or backdoor from sending data out or accepting commands. Keep the network off until you've booted into Safe Mode (next step) - you'll reconnect there briefly to download the scanner.

Why this mattersAMOS-family stealers exfiltrate browser passwords, keychain entries, and crypto wallet seeds within seconds of running. Cutting the network is the only way to stop ongoing exfiltration immediately.

2

Boot into Safe Mode and download Combo Cleaner

⏱ 5 min

macOS Safe Mode loads only Apple-trusted kernel extensions and skips most third-party LaunchAgents and user login items, so persistent Mac malware doesn't auto-run while you set up the scanner. Network access works normally in Safe Mode.

Apple Silicon (M1, M2, M3, M4)

1. Choose Apple menu → Shut Down
2. Wait until the Mac is fully off
3. Press and hold the Power button until "Loading startup options" appears
4. Select your startup disk (usually "Macintosh HD")
5. Hold Shift, then click Continue in Safe Mode
6. Log in - the menu bar will show "Safe Boot" in red

Intel-based Mac

1. Choose Apple menu → Restart
2. Immediately press and hold the Shift key as the Mac begins to boot
3. Release Shift when the login window appears
4. Log in - the menu bar will show "Safe Boot" in red

Once Safe Mode has loaded, turn Wi-Fi back on and download Combo Cleaner for Mac. Save the .dmg to your Desktop. You can disconnect Wi-Fi again before scanning if you want extra caution.

Identify - find what's hiding

~15 min

3

Inspect running processes with Activity Monitor

Tool: Activity Monitor⏱ 5 min

Open Activity Monitor (Applications → Utilities → Activity Monitor, or Cmd+Space and type "Activity Monitor"). Sort by CPU usage to spot cryptominers and runaway processes.

Click each unfamiliar process and choose View → Inspect Process (Cmd+I) to see:

• Path - anything in /private/tmp/, ~/Library/Application Support/<random-name>/, or with a generic-looking bundle ID is suspicious
• Code signing - Apple's processes are signed by "Apple" or "Software Signing." Adhoc-signed or unsigned binaries from third parties warrant investigation
• Open Files and Ports - shows what the process is touching on disk and network

Why this mattersMac malware often picks process names like "CoreServicesAgent" or "WindowServer" that look legit at a glance. The Inspect view shows the actual file path, which is what tells you it's not Apple's.

4

Map persistence with KnockKnock and inspect the launch paths

Tool: KnockKnock + Finder⏱ 7 min

Download KnockKnock by Objective-See (Patrick Wardle's free tool, the Mac equivalent of Sysinternals Autoruns). It lists every place macOS malware can persist in a single window: LaunchAgents, LaunchDaemons, Login Items, Cron Jobs, Browser Extensions, Kernel Extensions, Authorization Plug-ins, Mail Plug-ins, Quicklook, Spotlight, and more.

Run KnockKnock and toggle "Filter Signed Items" to focus on unsigned or non-Apple-signed entries. Click any suspicious item to see its file path and code-signing status.

If you'd rather check manually, open Finder → Go → Go to Folder (Shift+Cmd+G) and visit each path:

• /Library/LaunchAgents/ - system-wide, runs at login for any user
• /Library/LaunchDaemons/ - system-wide, runs at boot before login
• ~/Library/LaunchAgents/ - user-level, runs at this user's login
• ~/Library/Application Support/ - where adware drops its data folder, often with a random or app-mimicking name

Then check additional persistence locations in System Settings:

• Login Items & Extensions - System Settings → General → Login Items & Extensions. Click anything you don't recognize and remove it
• Background Items - same panel, "Allow in the Background" section. Mac malware often shows up as a background item with an obscure name
• Configuration Profiles - System Settings → General → Device Management (or "Profiles" on older macOS). Remove any Profile you didn't install yourself

Pro tipRight-click any suspicious .plist → Open With → TextEdit. The <key>Program</key> and <key>ProgramArguments</key> values tell you exactly what executable runs and from where. Don't delete yet - write down the file paths and entry names. We'll remove them after the Combo Cleaner scan in Step 7.

5

Check /etc/hosts and DNS settings

⏱ 3 minBuilt into macOS

Mac malware sometimes redirects bank, Apple, antivirus, and update domains to attacker-controlled servers via the hosts file or DNS settings.

Hosts file: Open Terminal (Applications → Utilities → Terminal) and run:

sudo nano /etc/hosts

Legitimate entries are commented with #. Any uncommented IP-to-domain mapping is suspicious - especially redirects for apple.com, icloud.com, your bank, or your password manager. Press Ctrl+X to exit nano without saving.

DNS settings: System Settings → Network → click your active connection (Wi-Fi or Ethernet) → Details → DNS. Confirm DNS servers point to your ISP, your router, or a known public resolver (Cloudflare 1.1.1.1, Google 8.8.8.8). Anything else has been hijacked.

Why this mattersA clean Mac with hijacked DNS is still a compromised Mac. You'll think you're at chase.com and you'll be at the attacker's clone.

Remove - scan and clean up

~30 min

Recommended antivirus: Combo Cleaner for MacDetects adware, info-stealers, cryptominers, and the LaunchAgent / LaunchDaemon persistence files they install. The 7-day free trial is available.

Download Combo Cleaner

6

Run a full Combo Cleaner for Mac scan

Tool: Combo Cleaner⏱ 20–30 min

Open the .dmg you downloaded in Step 2. Drag the Combo Cleaner icon to the Applications folder. Open it from Launchpad (or Applications), allow it to update its threat database, then click Start Combo Scan and let it complete fully. Review what it found and apply the recommended actions.

Why this comes before manual cleanupCombo Cleaner removes known adware, info-stealers, cryptominers, and the LaunchAgent persistence files they installed in one pass. Manual cleanup in Step 7 is for anything still left over.

7

Manually remove anything still present

⏱ 10 minTool: Finder

Reopen KnockKnock (or revisit the Finder paths from Step 4). Anything you flagged that's still present hasn't been caught by the automated scan. For each remaining suspicious entry:

1. Note the executable path the .plist references (right-click the .plist → Open With → TextEdit, look at <key>Program</key>)
2. Move the .plist to Trash
3. Move the executable file at the referenced path to Trash
4. Empty the Trash

Then go to /Applications and remove any unwanted apps the malware installed. Common adware-installed app names: MPlayerX, NicePlayer, MyShopcoupon, Advanced Mac Cleaner, Mac Cleanup Pro. Drag them to Trash, then check ~/Library/Application Support/ for any folder with the same name and delete it too.

ImportantSome malware files reappear after deletion because something else on the system recreates them. If a file returns within minutes, you have a remaining persistence point KnockKnock didn't show. Re-run Combo Cleaner or proceed to a macOS reinstall (see end of guide).

Recover - restore browsers and security

~15 min

8

Reset browsers and clear notification permissions

⏱ 5 min

Mac adware persists in browser extensions, search engine settings, homepage, and notification permissions. Reset each browser you use:

• Safari: Safari → Settings → Extensions - uninstall anything you don't recognize. Then Safari → Settings → Search - restore your preferred default search engine. Then Safari → Settings → Websites → Notifications - remove all unfamiliar sites. For a deep reset: Safari → History → Clear History → "all history."
• Chrome: visit chrome://settings/reset → "Restore settings to their original defaults." Then chrome://settings/content/notifications and remove unfamiliar sites.
• Firefox: open about:support → Refresh Firefox. Then check Settings → Privacy & Security → Permissions → Notifications.

Review installed extensions in each browser and remove anything you don't recognize, especially extensions you didn't install yourself.

9

Re-verify Gatekeeper, FileVault, and System Integrity Protection

⏱ 10 min

Some Mac malware tries to weaken built-in security to make persistence easier. Verify each is on:

• Gatekeeper (blocks unsigned apps): System Settings → Privacy & Security → scroll to Allow applications downloaded from → confirm "App Store and identified developers" is selected (not "Anywhere"). If the malware added itself to the allow-list, the entry appears in the same panel - remove it.
• FileVault (full-disk encryption): System Settings → Privacy & Security → FileVault → confirm "FileVault is on for this disk." If it was disabled by malware, turn it back on.
• System Integrity Protection (SIP): open Terminal and run csrutil status. Output should be "System Integrity Protection status: enabled." If disabled, you'll need to reboot into Recovery Mode and run csrutil enable from there.

Then run macOS Software Update (System Settings → General → Software Update) to apply the latest security patches.

Verify & secure

~15 min + 7 days

10

Change passwords from a clean device

⏱ 20 min⚠ critical for AMOS family

If the malware was an info-stealer (AMOS, Banshee, Cthulhu, or RustDoor families are extremely common on Mac), assume every password saved in your browser is compromised. So is your iCloud Keychain if it was unlocked while the malware ran. Change passwords from a different, known-clean device - your iPhone is fine if it's not infected.

Recommended order:

1. Apple ID first - it controls iCloud, Find My, Apple Pay, and the App Store
2. Primary email - the recovery hub for everything else
3. Banking and financial accounts
4. Password manager master password (if you use one)
5. Crypto wallet seed phrases - if you store any seed phrase or private key on the Mac, AMOS specifically targets these. Move funds to a fresh wallet from a clean device immediately, before changing other passwords
6. Social media, shopping, and remaining accounts

Where available, enable phishing-resistant multi-factor authentication (passkeys / hardware keys / authenticator apps) - SMS-based MFA is bypassable.

11

Verify the clean and monitor for 7 days

⏱ 5 min + 1 week monitoring

Reconnect to the network and run one final full scan with Combo Cleaner. Open System Settings → General → Login Items & Extensions and confirm nothing suspicious has reappeared. Open Activity Monitor and verify no unfamiliar process is using significant CPU.

Over the next 7 days, watch for symptom recurrence: high CPU when the Mac is idle, browser redirects returning, fake update prompts, or unfamiliar Login Items reappearing. If anything returns, you missed a persistence point and the procedure needs to be repeated - or you may have a deeper compromise that requires a clean macOS reinstall.

When to reinstall macOS instead

Manual removal isn't always the right answer. Reinstalling macOS from scratch is the only way to be 100% certain when:

• The malware reappears after every removal attempt
• A kernel extension or system-level component was modified
• Confirmed credential-theft malware ran with admin rights - the system likely has multiple unknown payloads
• The Mac is used for online banking, crypto wallets, business email, or anything where partial doubt isn't acceptable

macOS reinstall is straightforward: shut down → boot to Recovery (Apple Silicon: hold the Power button → Options; Intel: Cmd+R during boot) → Erase Mac → Reinstall macOS. Back up documents to external storage first, scan the backup with Combo Cleaner before restoring it, and reinstall apps fresh - never restore them from a backup of the infected system.

Important: Manual removal of Mac malware requires care - deleting the wrong .plist or system app can prevent macOS from booting normally. If you're not confident identifying system files from malicious files, run an automated scan with Combo Cleaner for Mac and stop there - that path catches the vast majority of consumer Mac malware without the risk of breaking macOS.

Frequently Asked Questions (FAQ)

My computer is infected with Shlayer malware, should I format my storage device to get rid of it?

Shlayer malware can be effectively removed without the need to format your device.

What are the biggest issues that malware can cause?

Malware can cause various problems (it depends on the type of the malware/its capabilities), such as identity theft, financial and data losses, slow computer performance, additional infections, and other issues.

What is the purpose of Shlayer malware?

Shlayer promotes adware (e.g., Pirrit, Bundlore, Cimpli and Geone) and other questionable apps, and shady search engines.

How did Shlayer infiltrate my computer?

It is known that Shlayer is distributed using torrent sites, fake Adobe Flash Player installers, websites that show fake virus, error, and other alerts, and installers for pirated software.

Will Combo Cleaner protect me from malware?

Combo Cleaner effectively identifies and removes a wide range of malware infections. However, it is important to note that advanced malware may conceal itself deeply within your system. Hence, running a full system scan is necessary to remove high-end malware.