Better to control any such impulses, as legal experts say that "hitting back" may break the law. For starters, unauthorized access to an attacker's system can put you in violation of the Computer Fraud and Abuse Act or states' trespass laws.
On the other hand, as David Willson, an attorney from Titan Info Security Group, said at this week's Hacker Halted conference, "If a hacker wants to sue you for unauthorized access, that might be a chance you're willing to take."
[ The FBI is beefing up its resources to defend against malicious hackers. Read more at FBI Expands Cybercrime Division. ]
Unauthorized access to an attacker's system is one thing; a full-blown cyber strike-back is another. Given all the potential responses, exactly what is allowed -- or at least tends to not be prosecuted? Here are nine facts to help keep your security operations in the legal and ethical clear.
1. Forget striking back, unless you're Georgia.
Online attacks may be sexy, but they're also illegal – unless, of course, you happen to be operating under the aegis of a clandestine U.S. government cyber-weapons program, or assisting a state intelligence or security service.
Take the country of Georgia, which recently outed an attacker through his webcam. Unfortunately, its techniques fall into the "Don't Try This at Home" camp for corporate security professionals, since Georgia's self-described "counter cyber-intelligence" effort involved infecting the attacker with his own Georbot malware. To do this, Georgian security experts infected a test machine with the malware, thus putting it under the control of the attacker's botnet. Then they copied a fake zip file containing the malware, re-titled "Georgian-Nato Agreement," onto the PC.
Helpfully, Georgia's Computer Emergency Readiness Team (CERT) had already gained access to the botnet's command-and-control server control panel. So after the attacker unzipped the file and executed it, infecting himself with his own malware, Georgian authorities were literally able to control his computer. They then activated the webcam and began studying the contents of his PC, obtaining information about his destination city, Internet service provider, and email, as well as his handle--Eshkinkot--according to a report released by Georgia's CERT, which blamed the attack on Russian security services.
2. Don't set malicious booby traps.
If striking back is out, what's the point? Focus on building a better defense. "We discourage people from full-on attacking back," said Paul Asadoorian, product evangelist for Tenable Network Security. He teaches an "offensive countermeasures" course with John Strand on tactics and measures that companies can take to improve their defenses while also adding, in his words, "a splash of offense."
A large portion of the course is devoted to reviewing relevant case law from both the digital and physical realms. "We're definitely aiming to put in the hands of practitioners techniques that they can use that are both effective at stopping attackers today, and which also won't land them in an orange jumpsuit," Asadoorian said, speaking by phone.
He references a case involving Eric Stetz, who decided to protect his apartment by creating a malicious booby trap involving a knife duct-taped to a crutch. When the landlord opened the apartment on a preannounced maintenance visit, he fortunately avoided injury, but Stetz was arrested on charges of reckless endangerment. "You should not be thinking of doing the digital equivalent of what this person has done, because the moral of the story is, the wrong person could fall into this trap," said Asadoorian. "You have to use good common sense."
3. Pursue reconnaissance.
Malicious booby traps are out, but some types of reconnaissance seem to be legally acceptable. In a case involving Jerome Heckenkamp, for example, a Unix system administrator at Qualcomm who was investigating an attack collected the IP and MAC addresses of the attacker and then hacked into the alleged attacker's computer, which he found belonged to Heckenkamp. Crucially, however, the administrator didn't delete any data or set any traps -- he only collected relevant information -- and a court ruled that he hadn't violated Heckenkamp's privacy. Heckenkamp ultimately agreed to a plea bargain that saw him released for time served.
Port scans, which might be considered an offensive countermeasure, also appear to be legally acceptable in some circumstances according to Asadoorian, who noted that many security researchers have used them to help reveal the quantity of Internet-connected devices with known vulnerabilities.
Still, many underlying legal questions remain unanswered. Veteran technology reporter David Pogue, for example, this month asked in Scientific American, "Does a public 'Find My iPhone' search violate personal privacy?" after he tweeted the address of the person who'd snatched his iPhone from an Amtrak train. While local police recovered the phone and the culprit admitted guilt, Pogue's tweet raised some people's privacy hackles. After investigating the issue, however, Pogue reported that "for the most part … both the legal and ethical ramifications of my crowd-sourced phone quest are nothing but murk."