How do I check if a malware download was successful on my iPad Pro?

Providing your iPad has been kept up-to-date with system software updates, you should not be overly concerned for your iPad being directly compromised by malware. Due to the sandboxed system architecture of iOS/iPadOS, unless jailbroken, your iPad is not susceptible to traditional malware infection per-se. However, as with all computer systems, there are still vulnerabilities and exploits to which you remain vulnerable. 

For older devices, no longer benefiting from regular security updates, the risk of an unpatched vulnerability being exploited increases. Regardless of the installed version of iPadOS, there are useful mitigations that can be used to significantly reduce your exposure to risk. For iPad, ensure that you have updated to the most recent version of iPadOS - the current version being iPadOS 18.5

The majority of threats to which you will be invariably exposed will surface via web pages or embedded links within email or other messaging platforms. Browser-based attacks can be largely and successfully mitigated by installing a good content and Ad-blocking product. One of the very best and most respected within the Apple App Store - designed for iPad, iPhone and Mac - is 1Blocker for Safari:

https://apps.apple.com/gb/app/1blocker-for-safari/id1365531024

1Blocker is highly configurable - and crucially does not rely upon an external proxy-service of dubious provenance, often utilised by so-called AntiVirus products intended for iOS/iPadOS. Instead, all processing by 1Blocker takes place on your device - and contrary to expectations, Safari will run faster and more efficiently.

Unwanted content is not simply filtered after download (a technique used by basic/inferior products), but instead undesirable embedded content is blocked from download. 1Blocker has also introduced its new “Firewall” functions - that are explicitly designed to block “trackers”. Being implemented at the network-layer, this additional protection works across all Apps. Recent updates to 1Blocker has introduced additional network extensions, extending protection to other Apps.

A further measure to improve protection is to use a security focussed DNS Service in preference to automatic DNS settings. This can either be set on a per-device basis in Settings, or can be set-up on your home Router - and in so doing extends the benefit of this specific protection to other devices on your local network. I recommend using one of the following DNS services - for which IPv4 and IPv6 server addresses are listed:

Quad9 (recommended)

9.9.9.9

149.112.112.112

2620:fe::fe

2620:fe::9

OpenDNS

208.67.222.222

208.67.220.220

2620:0:ccc::2

2620:0:ccd::2

Cloudflare

1.1.1.1

1.0.0.1

2606:4700:4700::1111

2606:4700:4700::1001

Security focused DNS providers intentionally "sink hole" known bad or malicious websites and resources - this providing an additional layer of protection beyond that provided by your device and its Operating System. These DNS services will, when used alongside 1Blocker or other reputable Content Blocker, provide defence in depth.

There are advanced techniques to further “harden” iOS/iPadOS (such as using DoH, DoT and DNSSEC). Apple has recently introduced its new Private Relay to its iCloud+ subscribers - in part employing ODoH (a variant of DoH) as an element of this new functionality. DoH and DoT are now natively supported by iOS/iPadOS, however these protocols are only surfaced through adding a management profile to the device; this is easily implemented through using a third-party App such as DNSecure:

https://apps.apple.com/gb/app/dnsecure/id1533413232

I hope this information and insight proves to be helpful. 

Download-based malware for iPad is very rare.

Phishing messages and spoofed messages and related scams and the rest are far more common. Endemic, even.

Recognize and avoid social engineering schemes including phishing messages, phony support calls, and other scams - Apple Support

Enable two-factor authentication on your Apple Account, and use unique passwords everywhere, as well. It’s phishing and scams and re-used passwords and similar vulnerabilities — and not malware — that cause most of the problems.

Rather less likely to be necessary here or in general, but if you want higher difficulties for malware, enable Lockdown:

About Lockdown Mode - Apple Support

if you don't Jail-break your iOS devices it's very remote for an iOS device to be infected by malware. The API programming language made available to developers to write apps is very limited in what you can do outside apples guardrails. that being said it's not impossible for a state agency or bad actor to intercept you data as you transmit it.

further reading, since an educated user is the best safety net in any computer network:

https://en.wikipedia.org/wiki/Category:IOS_malware

Did you call this friend and ask if they sent you the photos? If they did, then you can be certain it's not a scam or any type of malware.

If this friend says they did not send you any photos, then stopping the download is all you needed to do.

short answer… if your iPad firmware is up to date, don’t worry about malware. Your iPad has other issues.

Always read the senders address before doing anything? Is it an address you recognize? Often times you’ll notice something “is suspicious” about the senders address. If it’s shady then just block and delete. I must have 200 blocked numbers

Saegzz wrote:

Always read the senders address before doing anything? Is it an address you recognize? Often times you’ll notice something “is suspicious” about the senders address. If it’s shady then just block and delete. I must have 200 blocked numbers

It’s unfortunately become trivial to spoof sending email addresses and sending telephone numbers.

Yeah, lots of it is still rank junk, but the scams have been and will continue to improve.