Hackers posing as Merkel target ECB's Lagarde - German source

The signing ceremony on the adoption of the euro by Croatia, in Brussels

FRANKFURT (Reuters) -Unidentified hackers attempted to trick European Central Bank President Christine Lagarde into letting them open a messaging app account in her name by posing as former German chancellor Angela Merkel, a German source said on Tuesday.

The plot was quickly foiled without any information being compromised, an ECB spokesperson said.

"We can confirm that there was an attempted cyber incident recently involving the president," the ECB spokesperson said. "It was identified and halted quickly. No information was compromised. We have nothing more to say as an investigation is ongoing."

The incident was first reported by Business Insider.

A source familiar with the matter told Reuters hackers pretending to be Merkel messaged Lagarde asking her to disclose an authentication code that would have enabled them to open a WhatsApp account linked to the ECB chief's phone number. There was no official confirmation of this.

In a letter dated July 4 and seen by Reuters, Germany's domestic intelligence agency and Federal Office for Information Security warned German lawmakers that such a scheme was under way but without naming either of the targets.

"Specifically, the attackers exploit the existing relationship of trust between two high-ranking political figures," it said, referring to a "social engineering campaign".

While the tactics were not new, the German authorities said this scheme was unique in that it used the guise of top politicians.

"Affected parties who pass on authentication data to the attackers lose control over the respective messenger account. The attackers can then use this account, for example, to attack other people," the letter warned.

It said such a scheme typically asks mobile phone users to switch from SMS to WhatsApp, but also Signal or Telegram, both of which market themselves as securely encrypted apps.

Reuters has contacted Merkel's office for comment.

(Reporting by Francesco Canepa and Andreas Rinke; Writing by Rachel More; Editing by Catherine Evans and Alison Williams)