Knowledge base

Hardening iOS against spyware

A great deal of nonsense circulates about protecting your phone against spyware. More and more often, parties promise that they can detect mobile spyware and declare a device “clean”. That is a false promise. Such claims usually rest on specific hardware, which in turn is often based on the (open source) Mobile Verification Toolkit (MVT). Amnesty, the maker of MVT, stresses itself that a negative result does not prove a device is clean. Plenty of phones are not infected, but that cannot be established watertight, because an infected phone will usually give the same picture.

It is more useful to block the routes attackers use. This factsheet brings together the settings that yield the most. Every recommendation is based on threat information from public sources, with the substantiation in the notes. The order runs from no impact on your convenience to maximum protection. That way you can weigh up for yourself how much convenience you give up. No set of measures offers complete protection. They reduce the chance that an attack succeeds, and the damage if it does.

Two caveats. These measures reduce the chance of infection, but they do not remove an existing one. If you suspect your device is infected, replacement is best. Choose an iPhone with Memory Integrity Enforcement (iPhone 17, iPhone Air or newer) and apply everything below immediately on first use. Secure all your accounts again; see What settings do not take care of for you. This factsheet covers iOS only; the Android version is in preparation and will appear on the factsheets page.

Version 1, October 2026, based on iOS 27.

Basic hygiene: virtually no impact on use

Settings → General → Software Update → Automatic Updates → Download Automatically and Install Automatically → On

This protects against known vulnerabilities as soon as Apple fixes them. In March 2026 it emerged that the DarkSword spyware was infecting iPhones running iOS 18.4 up to and including 18.6.2 through hacked websites. Merely visiting such a site was enough. Apple has since closed this, but an estimated 220 to 270 million iPhones were still running a vulnerable version.¹
Settings → Apps → App Store → App Updates → On

iOS updates cover only the operating system; apps are updated separately. In August 2025 WhatsApp closed a zero-click hole in its iOS app, which attackers had combined with an iOS vulnerability against a small group of targeted individuals. Updating iOS alone therefore leaves part of the attack chain open.²
Settings → Privacy & Security → Background Security Improvements → Install Automatically → On

Apple can use this to fix vulnerabilities in between major updates, as it recently did for CVE-2026-20643, which allowed security to be bypassed through the web.³
Settings → General → VPN & Device Management → Mobile Device Management

Check whether a profile is listed here, which should not be the case on a personal phone. Remove unknown, untrusted profiles. There is a method in which criminals abused this functionality to hide the regular WhatsApp and Telegram apps and install malicious alternatives, without deploying any malware.⁴
Settings → Apps → Safari → Hide IP Address → Trackers and Websites

The Predator spyware uses a vector called Aladdin. It shows a malicious advertisement on the target’s phone: viewing it is enough for infection. The leaked documentation describes targeting based on your public IP address. Hiding it prevents that targeting, but only for Safari traffic; advertisements inside apps largely fall outside it. The “Trackers and Websites” option requires Private Relay (iCloud+). Without Private Relay you hide your IP address from trackers only.⁵
Settings → Privacy & Security → Tracking → Allow Apps to Request to Track → Off

This keeps apps away from your device’s advertising ID (ad ID). The Candiru spyware was recently distributed through targeted advertisements; display was enough for infection. Through Discover-Tech’s Controlium platform, spyware vendors selected targets by ad ID. Confiant found indications that they were displayed inside the Dutch Ministry of Economic Affairs. An advertisement does not establish targeting or infection, but it is a route. Targeting by IP address and cookie ID remains possible; this setting closes off one route, not all of them.^16, 33
Settings → General → Keyboard → Keyboards → remove third-party keyboards (or at least turn off “Allow Full Access”)

A keyboard with full access sees everything you type, including passwords. Citizen Lab found vulnerabilities in many of the keyboards examined that made keystrokes decryptable in transit. The research covered keyboards from Baidu and iFlytek, among others. There is no evidence of abuse, but the vulnerabilities are practically exploitable.⁶
Settings → Screen Time → Content & Privacy Restrictions → On → App Installations & Purchases → Installing Apps → Don’t Allow (both App Marketplaces and Web)

Do not install apps from outside the official App Store, because Apple does not carry out its full security reviews for those. If you want to maximise this, you can disable “Installing Apps” altogether; the App Store then disappears.⁷
Settings → Apps → Safari → Warn About Insecure Connections → On

Predator uses an injection system (Mars) that is placed at the telecoms provider. As soon as the target visits an HTTP page, it is silently redirected to the infection server. The system answers with a redirect to an infected page, after which the device is immediately infected. Since iOS 18.2 you can be warned about websites that use HTTP. Safari then loads the unencrypted page only after you confirm.⁸

Deliberate choices: limited impact on use

Settings → Wi-Fi → (i) next to the network → Auto-Join → Off

Turn off automatic joining for public or insufficiently trusted networks, because an attacker can imitate a trusted network. Apple states that with certain providers this can even expose your mobile identity.⁹
Restart regularly

The TriangleDB spyware from Operation Triangulation (2023) ran entirely in memory and disappeared on a restart. This does not prevent reinfection, nor does it protect against persistent spyware.¹⁰
Settings → [your name] → iCloud → Advanced Data Protection → On

Turn this on to end-to-end encrypt iCloud backups, Photos and Notes among others against access through the cloud. In the United Kingdom Apple no longer offers this option after government pressure, because it means less data can be compelled. Keep your recovery key safe or set a recovery contact, because Apple can no longer restore your data either.¹¹
Settings → General → AirDrop → Receiving Off

Researchers recently found three possibilities in AirDrop, including making the phone crash. Abuse in the wild has not yet been demonstrated.¹²
Limit the number of installed apps

Every app introduces vulnerabilities and so enlarges the attack surface. The Pegasus system checks which apps are on the device before an attack, such as WhatsApp or iMessage. Every messenger is another candidate route. The SparkCat trojan (2026) was even distributed through apps in the official App Store and could steal sensitive data.^13, 14
Separate personal and business use

The iPhone of an employee at a financial institution was infected while he scrolled past a football advertisement on Instagram. The malicious code started as soon as the advertisement came into view, checked the iOS version and deployed an exploit (DarkSword). The victim had to do nothing. The attack only worked on devices running an outdated iOS version, so updating is the first line of defence. If you cannot do without an app like Instagram, do not use it on the device that holds your business accounts and data.¹⁵
A VPN to a provider outside the country you are in

Predator also has an extension (Jupiter) that performs injection on encrypted HTTPS traffic, but only for websites hosted in the target’s own country. A VPN connection to a provider outside the jurisdiction routes the traffic encrypted past the local provider. That leaves both Mars and Jupiter without a foothold. This matters above all when travelling to high-risk countries. The trade-off: the VPN provider gains visibility into your traffic.⁸
Advertisement filtering through DNS

Use this as an additional layer of security, because Citizen Lab demonstrated in recent reporting on AdFection (October 2026) that targeted online advertisements could deliver Candiru spyware without any user interaction. Filtering of advertising networks by VPN apps can help block this attack method, but requires a privacy trade-off, because the VPN provider gains visibility into your DNS requests. Advertisements inside apps are not always blocked, so the benefit is limited.¹⁶

Reducing the attack surface: noticeable impact on use

Settings → Bluetooth → Off

Limit the attack surface when you are not using Bluetooth. Turning it off through Control Centre only breaks active connections; it does not disable Bluetooth entirely. In September 2026 several Bluetooth vulnerabilities became known that allowed attackers to execute their own code, among other things. Apple has patched them, but unknown vulnerabilities remain possible.¹⁷
Settings → Wi-Fi → Off

At elevated risk, limit the attack surface when you are not using Wi-Fi. In 2020 Project Zero built a zero-click exploit with which attackers took over an iPhone within radio range and made off with personal data. This has been patched, but unknown vulnerabilities remain possible. Here too: turning it off through Control Centre does not fully deactivate Wi-Fi.¹⁸
Settings → Apps → Messages → iMessage → Off

Apple’s messaging service is a known route for zero-click, in which your device is infected without you clicking on anything. In September 2026 Citizen Lab wrote that a Serbian activist was infected through iMessage with a zero-click exploit; without opening or tapping anything.¹⁹
Settings → Apps → Safari → Advanced → JavaScript → Off

Turn off JavaScript if you accept the limitations this imposes on browsing; disabling scripting reduces the attack surface. Citizen Lab showed that the Predator spyware could install itself through a malicious link opened with JavaScript.²⁰

Elevated risk: maximum protection

Settings → Privacy & Security → Lockdown Mode → Turn On Lockdown Mode → Turn On

This option is highly effective but unpopular. In apps you will still notice little of it; it shows mainly in web browsing: this mode blocks some technologies, so sites load more slowly, fonts drop out and images do not load. In Messages most attachments and links fall away, and FaceTime refuses calls from people you have not called for 30 days or more. Pegasus infections through PWNYOURHOME were not possible on devices with Lockdown Mode enabled, and in March 2026 it emerged that the Coruna spyware aborts an attack when this mode is active.^{21, 22, 34}
Buy a new iPhone

If you believe you are at elevated risk, buy an iPhone 17, iPhone Air or newer model with Memory Integrity Enforcement (MIE). The A19 chip in it protects against the memory abuse that advanced spyware such as Pegasus often relies on. Apply all the recommendations above immediately on first use, to reduce the chance that new exploit attempts succeed: an attacker can correlate identity, phone number, account or device identifiers and attack again. See also What settings do not take care of for you.²³
Developer Mode (deliberately not recommended)

Predator aborts an attack when Developer Mode is on. Even so, we do not recommend it. The spyware reports the reason for aborting to the operator, who then knows the target is taking measures and can choose another route. The effect has only been demonstrated for Predator, the option appears only after connecting to Xcode, and Jamf advises enabling the mode only when active security monitoring is running alongside it. At elevated risk, use Lockdown Mode.^24, 25

What settings do not take care of for you

Protect the people around you

NSO training material describes “close-circle infection” for targets who are security-aware. Colleagues, friends or family are then attacked in order to gather information indirectly. The advice: anyone at elevated risk should make sure their immediate circle applies these measures too.¹⁴
Check linked devices in Signal and WhatsApp

Go to Signal → Settings → Linked Devices and to WhatsApp → Settings → Linked Devices, and remove every device you do not recognise. Russian actors distributed QR codes disguised as group invitations or security warnings. Anyone scanning such a code unknowingly links their account to a device belonging to the attacker, who then reads along with every message. Such a link can go unnoticed for a long time.²⁶
Do not open links from unknown senders

Not every attack is zero-click. A lawyer in Pakistan received a link in WhatsApp from an unknown number, which led to Predator infrastructure.⁵
Never share a verification code, not even with “Apple Support”

In 2024 attackers sent Apple users password reset requests. They then called from a spoofed number on behalf of Apple Support to extract a one-time code with which they took over the account. A measure against this is Settings → [your name] → Sign-In & Security → Two-Factor Authentication → Security Keys → Set Up. With physical FIDO keys, a code passed on is worthless. Register two of them.²⁷
Treat any device that has been out of your control as possibly compromised

Switch your phone off if you are forced to hand it over. Reset your phone on return through Settings → General → Transfer or Reset iPhone → Erase All Content and Settings. In Serbia, phones were infected with spyware while they sat in a locker at a police station. That involved Android, but CVE-2025-24200 shows that physical access is a real route on iPhones too: an exploited bypass of the USB restrictions. So check that Settings → Privacy & Security → Wired Accessories → Ask Every Time is set.²⁸
Take an Apple threat notification seriously

Apple sends these notifications when it observes advanced spyware attacks directed at your device. In August 2026 alone, users in 110 countries were informed. Verify such a notification by going to account.apple.com yourself and signing in; a genuine notification appears at the top of the page. Never click links in the notification. Then enable Lockdown Mode and get expert help, for instance the Digital Security Helpline of Access Now.²⁹
After a (suspected) infection, a clean device is not enough

A Pegasus operator has a tab with passwords and authentication tokens from the device. This way, they can retain access to your online accounts even when your phone is no longer infected. After a threat notification or a suspicion, do not just replace or reset your device, but change all passwords and end active sessions from a trusted, clean device.¹⁴
Leave your phone outside the room during sensitive conversations

Do not rely on those green and orange dots. Predator can disable these indicators. That the microphone is deployed deliberately to pick up meetings is clear from NSO documents. Microphone recordings can be scheduled in advance and start automatically when it is known that the target has an important appointment in their calendar. On the iPhone 16 and newer the dots are driven outside the iOS kernel, so that even spyware with full kernel access should not be able to suppress them. Apple has not confirmed this, so leaving your phone outside is always better.^30, 31
A note on blocklists

Lists of known spyware servers (C2 domains) are of limited preventive use. NSO has its own team, White Services, buy anonymous infrastructure, partly paid for in cryptocurrency. Every customer gets separate infrastructure and accounts. Across hundreds of cases, Amnesty has never seen an attack account or infection domain used by more than one customer. Intellexa, too, has arranged its infrastructure to make detection harder since the publicity around Predator. A public list of C2 domains therefore offers no protection against new attacks. DNS filtering through VPN apps helps against advertising networks, not against spyware C2. After the fact, those domains are of limited value. Forensic tools such as MVT use them to recognise infections, but because infrastructure is unique per customer they will not lead to a ‘positive’ detection.^32, 14