Cyber hackers are believed to have infiltrated the computer networks of the Israeli military, security researchers at Blue Coat Systems Inc. reported as quoted in Israel Hayom.

According to the firm, the hackers were able to penetrate into associated networks of the IDF through a discreet espionage campaign. Trick emails prepackaged with attack software were sent to accounts registered on the servers.

The attack on the Israeli military is just one instance of a wider cyber espionage effort being carried out across the Middle East.

Researchers believe the four-month long campaign was most likely launched by Arabic speaking programmers since the default language setting in some of the programming tools was Arabic.

Waylon Grange, the security researcher at Blue Coat who discovered the infiltrations, explained that most of the hackers’ software were comprised on pre-existing, widely accessible tools and software, such as remote access to the Poison Ivy Trojan.

Based on the overall simplicity of the coding, Grange believes the hackers were working within a budget and time-frame. Most of the specialized work carried out by the hackers are centralized on the social engineering aspects, or human trickery, of the attack.

In various instances, the hackers sent emails to military addresses reportedly showing breaking military news or, in some cases, clips of “Girls in the Israel Defense Forces.”

Blue Coat explained that many of the emails included attachments that allowed the hackers to establish cyber “back doors” to access the military servers in the future and install further programs.

Some of the software which made its way onto government computers were found sending signals, or “beaconing” back to the hackers that the program was in place.

Despite Blue Coat’s finding, Israeli military officials said they were “not aware of hacking on IDF operational networks.”