How to remove XCSSET malware from the operating system

What is XCSSET?

XCSSET is malicious software designed to steal various information and capable of operating as ransomware.

Some of the main functionality of this malware includes modification of displayed websites, stealing of log-in credentials (i.e. usernames and passwords) and other data relating to browsing activity, collection of information from certain messaging platforms, data encryption for the purpose of making ransom demands for decryption, and so on.

XCSSET is a high-risk malicious program, and its infections pose a significant threat to device and user safety. This malware has been observed being distributed inadvertently by various developers - sharing their Xcode projects, which have been stealthily compromised and injected with malicious code.

XCSSET overview

XCSSET malware can exfiltrate files from the infected system. It can also steal information of interest from Notes and Evernote (note-taking organizing and archiving applications). QQ, Skype, Telegram and WeChat messaging apps are similarly targeted by this malicious program. XCSSET can take screenshots of the current screen and visited websites.

As mentioned, this malware can also operate as ransomware. I.e., it can encrypt files and display ransom-demand messages, which promise data recovery if a certain sum is paid. Browsers are not exempt from XCSSET's list of targets. The potential abuse over the development version of the Safari browser is particularly varied (theoretically, limitless).

To elaborate, the malicious program can: alter the displayed web pages; extract browser cookies; prevent users from changing their passwords and, if that fails, record the newly-set passwords; steal credentials of amoCRM, Apple ID, Google, Paypal, SIPMarket and Yandex accounts; obtain credit card details (specifically, from the Apple Store); interfere with cryptocurrency transactions by switching addresses of cryptowallets, and so on.

To summarize, XCSSET infections can cause data and financial loss, lead to serious privacy issues and identity theft. If it is suspected or known that XCSSET (or other malware) has already infected the system, use anti-virus software to eliminate it immediately.

Examples of other malware targeting macOS

Gmera, Tarmac, NUKESPED and AppleJeus are some examples of other Mac-specific malware. These malicious programs have a wide variety of purposes and capabilities. All malware is classified as a threat to device and user safety, and thus necessitate immediate removal.

How did XCSSET infect my computer?

At the time of research, distribution of XCSSET malware was dependent on its victims, and specifically affected users who develop software.

The malicious code would insert itself into Xcode projects (Xcode being a software development file, resource and information repository) and when the projects shared (e.g. uploaded to GitHub), the malware was distributed to other systems. XCSSET is also spread using other techniques.

In general, malware is proliferated via Trojans, spam campaigns, illegal activation tools ("cracks"), fake updaters and untrusted download sources. Trojans are malicious programs, some of which can cause chain infections (i.e. download/install additional malware).

Scam emails are sent by the thousand, during large-scale operations called "spam campaigns". These messages contain download links of infectious files and/or the files are simply attached to the emails.

Infectious files can be in various formats, (e.g. archives, executables, Microsoft Office and PDF documents, JavaScript, etc.) and when they are opened, the infection process is initiated. Rather than activating licensed products, "cracking" tools can download/install malware.

Fake updaters infect systems by exploiting flaws of outdated products and/or by installing malicious software rather than the promised updates. Malware is often downloaded unintentionally from untrusted channels such as unofficial and free file-hosting websites, Peer-to-Peer sharing networks and other third party downloaders.

How to avoid malware infections

You are advised to use official and trustworthy download sources. It is also important to activate/update products with tools or functions provided by legitimate developers. Illegal activation tools ("cracks") and third party updaters are commonly employed to spread malware.

Do not open suspicious or irrelevant emails, especially those with any attachments or links found in them, as this can result in high-risk infection. To ensure device integrity and user safety, it is crucial to have a reputable anti-virus suite installed. This software must be kept up to date, used to run regular system scans and to remove detected/potential threats.

If your computer is already infected with malware, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate it.

Update 20 April, 2021: It is known that XCSSET can now infect Mac computers with ARM64 (M1) and x86_x64 CPUs, and macOS Big Sur operating systems. Also, it uses malicious AppleScript files to create fake apps on macOS Big Sur and downloads icons (icon files) from a command and control server.

To make the fake icons look like the real ones, it modifies their "info.plist" files. It is important to mention that the latest XCSSET's modules modify icons so they would match the icons used in the version of the macOS installed on the infected machine.

Another important detail is that XCSSET loads its fake apps using its own "open" tool to avoid detection by macOS 11 security features.

It is also known that XCSSET now can steal sensitive information from websites such as 163[.]com, binance[.]com, Envato, Huobi, login.live[.]com, and nncall[.]net. Research shows that XCSSET can steal information from the Huobi page and replace cryptocurrency wallet addresses (change user's address to a specified address).

Update 18 February, 2025: A new version of the XCSSET malware is now targeting users' personal information, such as data from digital wallets and the Notes app. The malware now uses better methods to hide its code, making it harder to analyze, and has added two ways to stay on the system: using zshrc (to run the payload every time a new shell session starts) and dock (downloading a signed tool to modify dock items).

It also adds itself to Xcode projects in new ways, placing the payload in different build settings so it can run later. XCSSET creates a fake Launchpad app to launch both the real app and the malware at the same time.

By targeting Xcode projects, XCSSET can reach more victims, stealing data like logins, chat app info, browser data, Notes app details, digital wallet information, and system files. It is advisable to check and verify Xcode projects, especially those from unofficial sources, to avoid being exposed to XCSSET.

Update 13 March, 2025: XCSSET has been upgraded with more advanced obfuscation methods to bypass detection by security software. It also features improved persistence techniques, ensuring the malware stays on the infected system even after reboots or attempts to remove it. These updates make it more difficult to detect and eliminate.

Update March 28, 2025: A newly discovered variant of the XCSSET malware includes enhanced obfuscation methods, stronger persistence, and expanded capabilities. XCSSET uses multiple modules and persistence methods to remain on infected machines, such as altering .zshrc, leveraging the Dock method, and modifying Git pre-commit hooks.

The malware hides its activity and payloads with advanced encryption and API obfuscation techniques. It can also operate in a fileless mode, making detection and removal significantly more difficult. XCSSET also gathers a range of system information, such as macOS and Safari versions, firewall and SIP status, CPU details, and installed applications.

Furthermore, one of its modules scans for cryptocurrency wallet extensions in browsers and extracts sensitive data. Targeted wallets include BNB Chain Wallet, MetaMask, Phantom Wallet, TokenPocket, and TronLink. A separate JavaScript module is designed to extract data from the Notes app, which often stores credentials, API keys, and other sensitive information.

Update September 26, 2025: The latest XCSSET variant can steal Firefox data using a modified HackBrowserData tool, hijack the clipboard to swap crypto addresses with the attacker's, and use new persistence methods like LaunchDaemon entries and a fake System Settings app. So far, it has only been seen in limited attacks. Users are advised to keep macOS and apps updated to stay protected.

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 "XCSSET"?
• STEP 1. Remove PUA related files and folders from OSX.
• STEP 2. Remove rogue extensions from Safari.
• STEP 3. Remove rogue add-ons from Google Chrome.
• STEP 4. Remove potentially unwanted plug-ins from Mozilla Firefox.

Video showing how to remove adware and browser hijackers from a Mac computer:

Potentially 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 XCSSET malware, should I format my storage device to get rid of it?

While formatting your storage device can remove XCSSET malware, it also risks permanent data loss if your files are not backed up. Therefore, it is better to scan and clean your system with a trusted malware removal tool like Combo Cleaner.

What are the biggest issues that malware can cause?

Malware infections can lead to serious consequences, including financial loss, identity theft, system performance problems, further infections, and data encryption. The extent of the damage depends on the type of malware and its abilities.

What is the purpose of XCSSET?

Once the system is infected with XCSSET, the malware can steal sensitive information from various applications, including digital wallets and the Notes app. It can also take screenshots, encrypt files as ransomware, and display ransom messages. Additionally, it targets browsers by altering pages, stealing cookies, logging passwords, and obtaining credentials from services like PayPal, Google, and Apple.

How did XCSSET infiltrate my computer?

XCSSET (at least newer versions) typically infiltrates a computer through infected Xcode projects. These malicious projects are often downloaded from unofficial repositories or third-party websites.

Will Combo Cleaner protect me from malware?

Yes, Combo Cleaner can detect and remove nearly all known malware infections. However, advanced malware often resides deep within the system, so it is essential to perform a full system scan to ensure complete removal.