Japanese insurer Tokio Marine discloses ransomware attack

Tokio Marine Holdings, a multinational insurance holding company in Japan, announced this week that its Singapore branch, Tokio Marine Insurance Singapore (TMiS), suffered a ransomware attack.

The announcement came at the beginning of the week and contains little information about the incident outside the action taken to deal with the intrusion.

Limited attack

As the largest (revenue-wise) property and casualty insurance group in Japan, Tokio Marine Holdings is an attractive target for cybercriminals, who can use the breach to find and compromise customers of the organization.

Tokio Marine notes that the ransomware attack affected Tokio Marine Insurance Singapore and that other companies the group has in the country suffered no damage.

It is unclear how or when the attack unfolded and the damage it caused but the TMiS isolated the network immediately after detecting it and informed the local government agencies.

The parent company says that it can “can confirm that there is no indication of a breach of any customer information nor confidential information of the Group.”

Most ransomware attacks these days are also treated as data breach incidents because the attacker also steals files from the victim network before encrypting them.

However, a third party has been brought in to analyze the systems and assess the impact of the attack.

The company disclosed the incident on its website in both Japanese and English, apologizing to its customers for any “inconvenience and concern caused.”

Rash of attacks hitting insurers

Tim Starks of CyberScoop notes that Tokio Marine is the second insurer this week to announce a cyber attack, with Ryan Specialty Group also disclosing on Monday that back in April it detected unauthorized access on some employee accounts.

However, some of the larger insurers fell victim to ransomware attacks earlier this year.

In March, CNA Financial Corporation - the seventh-largest commercial insurance company in the U.S. - was breached by Phoenix CryptoLocker ransomware, which also stole files containing customer information.

In May, the Avaddon ransomware gang hit AXA branches in Thailand, Malaysia, Hong Kong, and the Philippines, claiming the theft of 3TB of data in the process.

The extortionist’s appeal for insurance companies has been explained by a representative of the REvil ransomware gang in an interview earlier this year with Dmitry Smilyanets, intelligence analyst at Recorded Future.

Going by the alias Unknown, the gang’s representative said that insurers are “one of the tastiest morsels.” Hacking them gets the attacker access to the company’s customer base and then they hit the insurer at the end.

“Yes, this is one of the tastiest morsels. Especially to hack the insurers first—to get their customer base and work in a targeted way from there. And after you go through the list, then hit the insurer themselves” - Unknown, REvil representative