Analysis The FBI has reportedly sought the go-ahead to use a custom spyware package to bug terrorists and other national security suspects. Indirect evidence suggests that the request was likely to have been approved.
An application to use the Computer and Internet Protocol Address Verifier (CIPAV) spyware program was sought from the secretive Foreign Intelligence Surveillance Court in 2005, according to papers obtained by Wired after filling a Freedom of Information Act request.
The Foreign Intelligence Surveillance Court rubber-stamps surveillance orders and covert entries in cases involving national security or terrorism. The court, established by the 1978 Foreign Intelligence Surveillance Act, is based at the Justice Department's headquarters. FISC hearings are closed.
Among the reams of papers released in response to Wired's request (largely composed of internal emails and technical documents) are affidavits submitted by the FBI to the FISC star chamber to use the CIPAV package. The software is designed to log a target's internet use, recording every IP address a suspect computer communicates with. It also performs an inventory of operating systems, installed and running applications and logs open ports, IP addresses and Mac addresses of targeted PCs.
The existence of CIPAV came to light in July when it emerged in affidavits that feds used the package to trace the perpetrators of high school bomb hoaxes. The FBI declined to answer Wired's follow-up questions on its use of the surveillance tool.
FISC approved 2,072 warrants it considered in 2005 and 2,181 in 2006, rejecting none. Five requests were withdrawn before a ruling was made. Given this track record it seems more than probable that FISC approved the use of CIPAV.
Law Enforcement Trojan ploy
US authorities are far from alone in seeking approval for the use of "remote forensic software" (AKA a law enforcement Trojan) to bug the PCs of terrorist suspects. The German government is reportedly in the process of hiring coders to develop "white hat" malware capable of covertly hacking into PCs ahead of plans to change German law to allow the practice. Proposals by German firm Digitask to develop software to intercept Skype VoIP communications and SSL transmissions leaked onto the net last month.
The wider use of encryption and VoIP is creating problems for law enforcement agencies. Law enforcement use of spyware tactics might, according to some law enforcement officials at least, level the playing field by providing a vital extra tool in the fight against terrorism.
However, the scheme is fraught with difficulties.
Would-be terrorists need only use Ubuntu Linux to avoid the ploy. And even if they stuck with Windows their anti-virus software might detect the malware. Anti-virus firms that accede to law enforcement demands to turn a blind eye to state-sanctioned malware risk undermining trust in their software, as evidenced by the fuss created when similar plans for a "Magic Lantern" Trojan for law enforcement surfaced in the US some years ago.
Graham Cluley, senior technology consultant at Sophos, said that its policy remained that it not give "special treatment" to malware written by the authorities.
"If CIPAV came into our labs we would add detection. The software would be unlikely to have a 'copywriter FBI' notice on it so it may be that we already detect it," Cluley told El Reg.
A seminal academic paper written by Fred Cohen in 1984 showed that it was mathematically impossible to write something that was undetectable, or by similar reasoning, to write a perfect antivirus scanner. Faced with that possibility law enforcement officials would have little option but to request security vendors to deliberately ignore their spyware, an approach Sophos reckons is unworkable.
"If a customer suspects they may be under surveillance and sends a Trojan horse to us, we're going to provide protection against it. We have no way of knowing if it was written by the German or US authorities and, even if we did, we wouldn't know whether it was being used by the police or if it had been commandeered by a third party wishing to spy on our customer," Cluley explained.
The picture gets even more complex if different nations develop their own law enforcement snooping software.
Cluley went on: "The Americans could theoretically write a piece of spyware to spy on criminals in its country and ask us not to detect it. The French may then ask us to detect the American spyware (in case the Americans use it against them). Who should we obey?"
"Security vendors can't play favourites," he added.
It would only require one security vendor (or indeed individual) to write a program which detects the authority's spyware and the idea of convincing the world to turn a blind eye to detecting would fall down like a house of cards, Cluley concluded.
Tapping a phone line and installing malicious code on a user's computer are sometimes compared as equivalent but important differences exist, according to Cluley. "Malicious code on a user's computer can be copied, archived, adapted and - potentially - used by people who do not work for the authorities to spy on completely innocent victims," he explained. ®