The company said it was experiencing “severe disruption” to its international export services and is temporarily unable to dispatch items overseas. It has yet to provide an update on when the incident is likely to be resolved and shipping would resume.
It is believed to have already left more than half a million letters and parcels stuck in limbo, according to reports at the end of last week.
The attack is suspected to have come from a Russian-linked ransomware gang called Lockbit, as reported first by the Telegraph.
A Royal Mail distribution centre in Northern Ireland revealed its printers began “spurting” out copies of a ransom note on Tuesday, saying “your data are stolen and encrypted.”
Lockbit, which is believed to have close links to Russia, was also behind a major hack of car dealership Pendragon last year, which refused to pay a ransom payment of $60m.
Royal Mail would not comment on the hacking reports, but said it had launched an investigation...