Why does my iPhone keep saying I have a virus?

Contact Telstra to confirm the message. Do not call any number or use a link from the message, you will need to get the contact information from their official website or off your billing statement.

Note that Telstra is aware of the common scam message that claims to come from them saying you have a virus.

In this scam, an email is received which claims that Telstra has received a number of complaints about your email account sending viruses. The email has a link to a malicious website which claims to help you "scan for viruses", or, in some cases, to download (fake) anti-virus software.

https://www.telstra.com.au/cyber-security-and-safety/active-scams

Any message like that is a scam. A non-jailbroken phone cannot be hacked, get a virus, or get malware.

Two common ways you will see that fake message:

• Ad in a game you are playing
• When web browsing, a less than legitimate site is paid to pop up that fake message.

It should be easy to determine which of these 2 the case may be.

It's a scam ad, most likely coming from one of your apps, usually a game.