Online scammers are using the Christchurch shootings as an opportunity to try to steal money, with government cybersecurity agency CERT and Westpac both receiving reports of scams.

Photo: 123rf

This afternoon, Westpac warned an email scam using its branding is circulating, asking for donations for the victims of the mosque attacks.

The attackers are requesting money through emails, text messages and fraudulent donation sites.

Westpac head of financial crime and security Tiffany Ryan said the scams were "horrific".

"I think it's really sad where areas of society see vulnerabilities and exploit these," she said.

"We have got a city that is absolutely in shock and people trying to do the right thing and donating.

"And people trying to take advantage of that is not okay."

Ms Ryan said fewer than 10 reports of scams had been made by customers but her team had taken them "very seriously" and was working to shut them down.

She said it was not the first time she had witnessed tragedy-related scams.

"It is quite typical for people in this area of society to try and take advantage of an opportunity," Ms Ryan said.

"That's why, across the industry, we have really robust controls in place to try and find these types of activity and take them offline."

CERT said it was additionally dealing with malicious video content being spread and local websites being defaced to promote political messages.

CERT said some websites were receiving threats of denial-of-service attacks, which would take them offline.

The agency said there are official channels to donate money to the victims of the mosque attacks.

It recommends that anyone wishing to donate seek out official platforms and banks instead of using links in emails and on social media.

In a statement, the United States Department of Homeland Security said US-based contributors are also being targeted.

The organisations are warning people to check donation links are from a trusted source before offering any card details.

Westpac said the email scams had done little to hinder its legitimate collection of donations for the Christchurch Foundation - Our City, Our People Fund.

For those wanting to make donations, the correct account number is 15-3976-0091104-080.