FlexibleFormat Adware (Mac)

What is FlexibleFormat?

FlexibleFormat is an app classified as adware, and it has browser hijacker traits. Due to the dubious methods used to distribute FlexibleFormat and similar software, they are also categorized as PUAs (Potentially Unwanted Applications).

FlexibleFormat adware

FlexibleFormat adware overview

Adware enables the placement of third-party graphical content (e.g., pop-ups, banners, coupons, surveys, etc.) on visited websites and/or other interfaces. This software can diminish the browsing experience and pose a threat to device/user safety.

The displayed advertisements promote various untrustworthy and malicious sites. What is more, some intrusive ads can download/install software (e.g., PUAs) - when clicked on.

Browser hijackers assign fake search engine addresses as browsers' homepage, default search engine, and new tab/window URLs. Hence, web searches performed via the URL bar and new tabs/windows opened - redirect to the promoted address.

Most fraudulent search engines cannot generate search results, so they redirect to legitimate ones (e.g., Bing, Google, Yahoo, etc.). Browser hijackers also employ persistence-ensuring techniques - to prevent browser recovery.

Most PUAs (adware and browser hijackers included) can track data. The gathered information (e.g., browsing activity, personally identifiable details, etc.) is shared with and/or sold to third-parties.

To summarize, the presence of unwanted software on devices can lead to system infections, serious privacy issues, financial losses, and identity theft.

Threat Summary:
Name	Ads by FlexibleFormat
Threat Type	Adware, Mac malware, Mac virus
Additional Information	This application belongs to Adload malware family.
Symptoms	Your Mac becomes slower than normal, you see unwanted pop-up ads, you are redirected to dubious websites.
Distribution methods	Deceptive pop-up ads, free software installers (bundling), fake Flash Player installers, torrent file downloads.
Damage	Internet browser tracking (potential privacy issues), display of unwanted ads, redirects to dubious websites, loss of private information.
Malware Removal (Windows)	To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Combo Cleaner. Download Combo Cleaner 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.

Adware in general

DefaultEntry, LeadingSystem, LatestStructured, and PrinterCyberSpace are some examples of adware. This software appears innocuous and offers "useful" features that are seldom operational. In fact, this is true of nearly all PUAs. The sole purpose of these apps is to generate revenue at user expense; hence, functionality and user safety are irrelevant.

How did FlexibleFormat install on my computer?

PUAs can be downloaded/installed together with other programs. This false marketing tactic of packing regular software with various additions - is named "bundling". Intrusive ads spread PUAs as well. Once clicked on, the advertisements can execute scripts to make downloads/installations without user permission. PUAs can also have "official" download sites.

How to avoid installation of potentially unwanted applications?

It is strongly recommended to research software and download from official and verified channels. Dubious sources, e.g., unofficial and freeware websites, Peer-to-Peer sharing networks (e.g., Torrent clients, Gnutella, etc.), and other third-party downloaders - commonly offer bundled/harmful content.

Download/Installation processes increase the risk of allowing unwanted/malicious programs into the system. Therefore, it is crucial to read terms, study available options, use the "Custom/Advanced" settings, and opt-out of all additions.

It is just as important to exercise caution when browsing. Intrusive adverts appear legitimate yet redirect to highly questionable sites (e.g., gambling, pornography, adult-dating, etc.).

In case of encounters with such ads/redirects, the system must be checked and all suspicious applications and browser extensions/plug-ins detected - removed without delay. If your computer is already infected with FlexibleFormat, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate this adware.

Pop-up window displayed once FlexibleFormat adware's installation is over:

Pop-up displayed once FlexibleFormat installation is complete

FlexibleFormat adware's installation folder:

FlexibleFormat adware install folder

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:

DOWNLOAD Combo Cleaner

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 FlexibleFormat?
STEP 1. Remove FlexibleFormat related files and folders from OSX.
STEP 2. Remove FlexibleFormat ads from Safari.
STEP 3. Remove FlexibleFormat adware from Google Chrome.
STEP 4. Remove FlexibleFormat ads from Mozilla Firefox.

Video showing how to remove FlexibleFormat adware using Combo Cleaner:

FlexibleFormat adware removal:

Remove FlexibleFormat-related potentially unwanted applications from your "Applications" folder:

mac browser hijacker removal from 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.

DOWNLOAD remover for malware infections

Combo Cleaner checks if your computer is infected with malware. 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.

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).

Browser showing redirected search results from a hijacked search engine

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.

Finder window showing suspicious .plist files in LaunchAgents folder

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.

Browser showing fake Adobe Flash Player update prompt

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.

Activity Monitor showing a process consuming high CPU

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

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.

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)

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

Intel-based Mac

Choose Apple menu → Restart
Immediately press and hold the Shift key as the Mac begins to boot
Release Shift when the login window appears
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

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.

Activity Monitor showing the Inspect Process panel for a suspicious process

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.

KnockKnock main window showing categorized persistence list

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

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.

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:

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

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.

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

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:

Apple ID first - it controls iCloud, Find My, Apple Pay, and the App Store
Primary email - the recovery hub for everything else
Banking and financial accounts
Password manager master password (if you use one)
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
Social media, shopping, and remaining accounts

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

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.

System Settings Login Items showing a clean list

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)

What harm can adware cause?

Adware can decrease user experience by diminishing browsing quality and system performance. This software also usually has data tracking abilities, which makes it a threat to user privacy. Adware-delivered adverts are often dubious/malicious and can cause severe problems.

What does adware do?

Adware stands for advertising-supporting software. It is designed to deliver intrusive ad campaigns, i.e., display adverts on any visited site and/or different interfaces.

How do adware developers generate revenue?

Adware developers generate revenue by promoting various websites, applications, products, services, and similar. Most of the profit is from affiliate programs.

Will Combo Cleaner remove FlexibleFormat adware?

Yes, Combo Cleaner will scan your device and eliminate all installed adware-type applications. On the other hand, manual removal might be ineffective. Even if the software itself is (manually) removed - various file leftovers might remain in the system. Furthermore, such remnants can continue running and causing issues.