Seculert CTO Aviv Raff told Reuters that earlier this month hackers took control of around 15 computers including the Israel's Civil Administration computer which monitors Palestinians in Israeli-occupied territory.
The firm declined to identify other 14 computers targeted by the hackers. An anonymous source told Reuters these included companies involved in supplying Israeli defense infrastructure.
The latest attack is appeared to be originated from US servers. However, experts noticed some similarities to previous attacks. The firm suspects the Palestinians to be behind the cyber attack.
The firm hadn't determined what hackers did after gaining access to the systems. It believes that hackers had access to the infected computers several days.
Xtreme RAT is the remote access trojan that gives hackers complete access to the infected systems. An attacker is able to steal any documents or execute any other malware code in the system.
The same malware has been used in several other targeted-attacks including attacks targeting 'the Israeli police department', 'syrian anti-government activists' and other governments.