Israeli cyberactivists are inviting pro-Israeli surfers to install a tool that attacks websites associated with Hamas.

This "Patriot" tool effectively turns the computers of sympathisers of the Israeli cause into zombies - albeit willing, complicit ones - in the control of Israeli hackers.

The hackers are working under the banner of the Help Israel Win collective, which was formed last month at the start of the conflict in Gaza. "We couldn't join the real combat, so we decided to fight Hamas in the cyber arena," one of the group's organisers, 'Liri', told Wired.

The package developed by the group is designed to overload websites associated with Hamas, such as qudsnews.net and palestine-info.info, with spurious traffic. Israeli hackers claim that 8,000 have downloaded and installed the Patriot software.

Conflict in cyberspace is one aspect of a propaganda offensive that has accompanied the war in Gaza, and the decades-long Israeli-Palestinian conflict. Help Israel Win is vague about how its Patriot software works, preferring instead to stress its opposition to Hamas, which has the stated aim of destroying the state of Israel.

The Patriot package, according to Help Israel Win, "unites the computer capabilities of many people around the world. Our goal is to use this power in order to disrupt our enemy's efforts to destroy the state of Israel. The more support we get, the more efficient we are."

SANS Institute security researchers warn that the Patriot tool leaves the door open to abuse. "While at the moment it does not appear to do anything bad (it just connects to the IRC server and sites there - there also appeared to be around 1,000 machines running this when I tested this) the owner can probably do whatever he wants with machines running this," SANS researcher Bojan Zdrnja writes.

A Help Israel Win representative conceded to Wired that "the Patriot code could be used as a Trojan. However, it is not used as such, and will never be."

"The update option is used to fix bugs in the client, and not to upload any malicious code. The project will close right after the war is over, and we have given a fully functional uninstaller to [remove] the application," a representative added.

It's not particularly clear how effective the Patriot tool has been in silencing allegedly pro-Hamas websites, but Help Israel Win has been forced to repeatedly shift its website location in response to attacks for hackers sympathetic to the Palestinian cause, Wired adds.

Security tools firm Arbor Networks reported earlier this week of an increase in botnet attacks on Israeli targets as well as confirming that Help Israel Win was offering what it described as a "simple Windows tool" to target Palestinian websites.

"This is an example of DDoS attacks being used as a form of street protest and something that is becoming increasingly common," said Arbor researcher Jose Nazario.

Other experts confirm that hackers from the wider Muslim world are piling in on behalf of the Palestinians. "Our observations suggest that a large number of Web sites have been defaced by a variety of hacker groups from Iran, Lebanon, Morocco and Turkey, and the trend is accelerating," said Bruce Jenkins, a retired Major with the US Air Force and consultant with application security firm Fortify Security. ®