“Hello Again! We have news for you,” the Black Shadow group wrote in a message circulated on social media on Friday evening.
“You probably could not connect to many websites today. ‘Cyberserve’ company and their customers hit by us. You may ask what about Data? As always, we have lots of it. If you don’t want your Data leaked by us, contact us soon.” the hackers added.
The websites of a number of Cyberserve’s customers were unavailable on Saturday morning.
According to a report published by the Israeli English-language daily newspaper Jerusalem Post, the data seized by the hackers covers a wide variety of businesses, including Dan and Kavim public transportation companies, the Pegasus travel company and the blogsite of the Kan public broadcaster.
The hacker group released what they say is data from Israeli bus line Kavim on Telegram on Saturday.
“They did not contact us …So first data is here ! “Kavim Bus” ‘https://www.kavim-t.co.il/,'” the Black Shadow said on Telegram, sending with it a picture of what appears to be a database containing Israelis’ personal information.
“If you do not contact us , it will be more,” the group added.
Last year, the Black Shadow attacked Israeli vehicle insurance company Shirbit, and reportedly demanded bitcoins as ransom.
The company, however, said it wouldn’t pay, leading to the dark web sale of information stolen from the firm.
The Black Shadow’s December 2020 attack on Shirbit was the largest cyberattack against an Israeli company at the time.
Hebrew-language media reports allege the Black Shadow is an Iran-backed group.
A 2020 survey showed that Israeli companies paid out over $1 billion to hackers as ransom in 2020, with the 2021 figure expected to increase.