Who are the group behind this week's CIA hack?

The posting on Twitter was brief and to the point: “Tango down – cia.gov – for the lulz”. Barely a month seems to go by without some sort of high-profile hack attack making global headlines and June is turning out to be a cracking month for online mischief makers.

Late on Wednesday evening the public homepage of the CIA was briefly taken offline after it was targeted by LulzSecurity, the latest hactivist collective to spawn on the internet and leave a merry wake of destruction in its somewhat erratic path.

If the beginning of 2011 was dominated by Anonymous, the shadowy cyber network that launched a series of high profile web-protests in defence of WikiLeaks, the summer has been seized by LulzSecurity.

A relative newcomer to the hactivist scene, LulzSec (as they like to be known) have claimed successful hacks and disruption attacks against – among others – Sony, the NHS, Fox News, the US Senate, Pron.com and a string of online gaming communities. And all of this has happened in little more than a month.

It is often difficult to tell whether a website has been truly taken offline by a targeted assault or because the claim that a site has been compromised drives so much extra traffic towards it that it has to close. Either way, Wednesday’s short assault on the CIA’s public homepage is LulzSecurity’s most brazen act yet and may have earned them some particularly powerful enemies within America’s law enforcement community.

Who LulzSecurity are remains a closely guarded secret. Like Anonymous, the group is a disparate online network, made up of supporters around the world who collectively lend the combined power of their hard drives and hacking skills to pull-off eye-catching assaults.

But while Anonymous has something of a self-important political activist air about it – choosing targets that they are ideologically opposed to – LulzSecurity seems to be motivated by a more simplistic urge; the desire to have fun and cause a bit of mischief.

Their method of targeting is erratic and chaotic. While there appears to have been overly political attacks, such as the recent assaults on Sony, the CIA and the Senate website, LulzSecurity has no problem with trying to breach porn and gaming websites which could lead to a backlash from the online community.

Then there’s the movement’s figurehead – a fictional character with a dodgy French accent who goes by the name of Pierre Dubois.

On the same day that it attacked the CIA’s public page, LulzSecurity said it would begin taking requests from members of the public for where they should aim their next distributed denial of service (DDoS) attacks, a relatively simple and blunt disruption technique which takes a website temporarily offline by inundating its servers with requests for information.

The group posted a voicemail number for people to leave requests. Those phoning the Ohio based number would get a message, read out in a faux French accent, stating: "You have reached the whistle box of Pierre Dubois. We are not present right now because we are busy ruining your Internet. Leave a message, and we will get back to you whenever we can." LulzSecurity claims it has since temporarily taken down seven more sites using DDoS attacks requested by the public.

Taking requests is not necessarily new – Anonymous activists have long used chat boards to vote on who their next targets should be. But the fact that LulzSec opted for a comedy phone line testifies to the group’s eccentricity. The group’s website meanwhile invites followers to jump on board “The LulzBoat” accompanied to the theme music to the 70s American TV show, The Love Boat.

Generally security experts classify hackers into three categories. White-hat hackers are those who spend their days breaking into websites to deliberately expose their weaknesses, altruistically alerting a site’s owner before any damage can be done. The black-hats deliberately go out of their way to sabotage, steal data or install spy-ware for personal gain. And in the middle are the grey hats who do a bit of both.

Like Anonymous, LulzSecurity falls squarely into the grey camp. The group claims to be exposing security vulnerabilities in websites and organisations purely for "fun". But their willingness to dump the stolen data and details they uncover online pushes them towards the black hats.

The group’s largest heist occurred last month when it successfully broke into the website of Sony Pictures and made off with what they claimed were 1m user details including emails, passwords and addresses. Sony claimed the real figure was closer to 40,000 but the breach was deeply embarrassing for the Japanese tech giant which had only just begun to recover from a series of major data thefts that shutdown the entire Playstation Network for the best part of a month.

Most damning was the revelation that LulzSecurity’s followers used a relatively simple hacking technique known as an SQL injection to break into the Sony Pictures website and then came across huge tranches of customer information that was unencrypted.

“From a single injection, we accessed EVERYTHING,” boasted a LulzSec post on its website. “Why do you put such faith in a company that allows itself to become open to these simple attacks?”

There are theories that LulzSec could be an offshoot of Anonymous, possibly old hands who grew weary of Anonymous’ increasingly political grandstanding and wanted to get back to making mischief. They certainly share Anonymous’ loathing of Sony but LulzSec’s Twitter feed is filled with exhortation to go harass and annoy Anonymous supporters in an online trolling campaign.

As to whether LulzSecurity poses a threat or not, the security community remains somewhat divided.

"While some people think this is a fun game that can also help point out corporate security weaknesses, the truth is that companies and innocent customers are - in the worst cases - having their personal data exposed," said Graham Cluley, senior technology consultant at Sophos. "There are responsible ways to inform a business that its website is insecure, or that it has not properly protected its data. What's disturbing is that so many internet users appear to support LulzSec."

Josh Corman, research director at The 451 Group, an IT analysis and research firm, told BankInfoSecurity.com website that while LulzSecurity have quickly morphed into a formidable menace, their abiding philosophy is making mischief rather than causing damage.

"These are ideological insiders that have access; this is more like Fight Club; they do your laundry, they work in the mailroom," he said. "This is a whole counterculture thing; especially in a time when people feel powerless. They find this empowering."