Russian hackers have targeted messaging apps used by Dutch officials, intelligence services in the Netherlands said on Monday, part of what they described as a "large-scale global cyber campaign."

The hackers are aiming to crack WhatsApp and Signal chats used by dignitaries, military personnel and civil servants, the AIVD spy agency said in a report, without specifying which other nations had been targeted.

"The Dutch services also believe other persons of interest to the Russian government, such as journalists, may possibly be targeted by this campaign," the AIVD said in a statement.

The most commonly used method is for the hackers to pretend they are the Signal Support chatbot to persuade users to hand over their security details.

Another method is for hackers to take advantage of these apps' "linked devices" function, where users can chat on their laptops or PCs.

Once a chat has been compromised, the hackers can read all messages, said the AIVD, warning they "likely gained access to sensitive information through this campaign".

"Despite their end-to-end encryption option, messaging apps such as Signal and WhatsApp should not be used as channels for classified, confidential or sensitive information," said military intelligence director Peter Reesink.

Last March, the Pentagon warned staff in a memo last week against using Signal, citing threats from Russian hackers.