OnNet Services, a Poland based cyber security firm which foretold theft of Sh11 million at four Barclays Bank Auto Teller Machines (ATM) over the Easter holiday, has linked three local hacker communities to bank heists in Kenya.

The agency had on April 17 through a tweet warned that a hacker cartel going by the name SilentCards was targeting an institution during Easter festivities.

"We believe this threat actor is still active in different infrastructures and is planning to attack another institution this Easter by running huge transactions. By raising community awareness, we intend to minimize damage and loss to your customers," the firm also published the information on its blog two weeks ago.

The firm has also unearthed information about a server that was used by hackers early last year to loot Sh400 million from a local bank.

"Due to the fact the institution is not our client and has not directly or indirectly contacted us for approval to issue a statement, we can’t name it, rather we can provide details of how such a heist occurred according to our research, observations and intelligence collection,’’ the firm said.