A Closer Look at CIA-Linked Malware as Search for Rogue Insider Begins

The CIA and FBI reportedly have launched a joint investigation to discover who leaked thousands of confidential documents that contained descriptions of hacking tools used by the CIA to break into computer systems, smartphones, and smart televisions.

Sources close to the investigation say US intelligence agencies are hunting a CIA employee or contractor with physical access to the documents, which were stored in a "highly secure" agency division, according to CBS News, which broke the story on this latest development.

In March, WikiLeaks publicly disclosed documents it claims it received from a former US intelligence contractor. The files, collectively named Vault 7, included information on zero-day vulnerabilities for Windows, Android, and iOS, as well as exploits against routers and smart TVs.

Shortly after the WikiLeaks dump, cybersecurity firms connected the Vault 7 documents with a cyberespionage group known for targeting governments and private companies with a variety of tools. Each company has a different nickname for the group, which many believe to be the CIA.

Kaspersky Lab calls the group the Lamberts and claims its tools target Windows and Max OS devices. Symantec calls it Longhorn and says it exclusively attacks Windows targets.

Symantec started looking into these tools three- to four years ago, says Vikram Thakur, principal research manager at Symantec Security Response.

Thakur in an interview shared details of some of the tools Symantec discovered in its research on Longhorn's capabilities, how they are different, and their goals for targeting victims. The hacking tools target specific organizations and also give the attacker full access to communicate with users, he says.

"These tools are primarily backdoors with different capabilities," he explains. "They allow the attacker to ask any and all commands to the end user."

None of the tools discovered were used for mass surveillance, but for observing activity and gathering information from particular organizations. It's difficult to know what the specific commands were for, but Thakur says they were not being used to activate microphones and listen to conversations. They were looking for information: documents, meeting notes, and intellectual property.

"Some people might write malware with the intention of collecting hoards of information. This was not that type," says Thakur.

At the start of Symantec's Longhorn research in 2014, Plexor was the first particular threat to appear, Thakur says. At the time, the Trojan had only been seen on several Windows machines within one organization. Plexor contained information on the network architecture specific to the victim business, and would arrive via embedded Word document in a spearphishing email.

The team then unearthed Longhorn 1, which shared code with Plexor but had a "completely different toolset," he continues. Each sample of the Longhorn malware had a different set of keywords, but version numbers (3.5, 3.6, etc.) indicated it was part of an organized pattern.

Longhorn 2, another tool associated with the group, was discovered when his team was hunting for additional samples of Longhorn 1 in the wild. It's similar to the first version but has different functionality and lesser capabilities, says Thakur. Both were built to communicate with a specific command and control server, unique to the sample and victim.

Corentry is the next evolution in Longhorn's toolset. Like Longhorns 1 and 2, it's a backdoor designed to monitor activity and collect information, and it shares similar code and techniques to the other two tools.

While the organization using these tools was "extremely organized and driven by process," there was overlap in the use of these malware tools.

"We can see on a timeline that none of these tools were exclusively used at any point in time," says Thakur. This is a sign that multiple people were using the same code against a handful of organizations around the world at the same time, he says.

The tools were mostly used in countries "that we would consider of national interest," he continues, though he can't speak to specific countries or businesses. There was one instance in which a Corentry file infected a machine in the US, but it was quickly uninstalled, indicating it may have been launched by mistake.