It's a storyline that sounds ripped right from the pages of a spy novel. An Argentinian prosecutor dies in his apartment under mysterious circumstances. The death happens the day before he's due to testify to his country's legislature—he's going to claim a cover-up by the Argentinian president of details about a bombing that happened decades ago. Just a day prior he tells a journalist he fears for his life.

And now, months after his death, cybersecurity researchers are finding details falling into place that show his phone was completely owned by a unique version of the AlienSpy remote access tool (RAT). The circumstances around the infection of Alberto Nisman's Motorola phone were sussed out by Morgan Marquis-Boire, the director of security at First Look Media, who at Black Hat USA last month reported publicly what he found. According to researchers following up this week with further analysis of this incarnation of AlienSpy, the whole situation shows the human significance that digital attacks can have in situations like these.

"Attacks in the digital world are often a consequence of ongoing events in the real world," says Thoufique Haq, security researcher for Proofpoint, which this week released some findings from its analysis of the payload that Marquis-Boire believes sat on Nisman's phone for 6 weeks. "It is unclear whether this attack payload has any relevance to death of Alberto Nisman, but the payload analyzed nonetheless shows how the immense capability that a malware payload provides."

First brought to the forefront of the security limelight last April, AlienSpy is a more advanced refinement of previous RATs like Frutus and Adwind. In addition to keeping the core ability of completely compromising remote systems and mobile devices, AlienSpy's differentiator for attackers has been its sandbox evasion and antimalware disabling features. According to experts at Fidelis who first brought attention to AlienSpy this spring, the tool was being used to deliver the Citadel banking Trojan and to maintain persistence particularly within targeted critical infrastructure companies.

In this specific instance, Marquis-Boire discovered the connection to AlienSpy after reading an account this summer that gave the full file name of a JAR file that seemed to be the payload that infected Nisman's phone. When Marquis-Boire looked it up on VirusTotal, the search came up with only a single instance of that file. According to Proofpoint, that file itself may not have even been the intended payload for the prosecutor's phone.

"Android payloads are typically APKs (Android Application Package) or native binaries compiled for ARM processors," Haq says. "While technically possible, it is not trivial to get JAR payloads to run on an Android operation system without installing a Java emulation engine. Instead, it is more likely that the payload was intended to be loaded on a desktop environment but may have been inadvertently downloaded on the Android phone, possibly through email or another vector."

Nevertheless, it did provide a valuable breadcrumb in the analysis of this particular instance of AlienSpy, which Haq reports packaged up that JAR in an additional layer of obfuscation that's not usually seen in most AlienSpy payloads in the wild. The payload showed a considerable range of features, says Haq, explaining that they were extensible through secondary plug-ins that could be pushed down to the targeted machine. While the analysis proved a good academic exercise, it is unlikely that any researcher will be able to use it to figure out who exactly placed it on Nisman's phone. But it does stand as yet another example in the growing cadre of RATs that are used both for political and economic espionage today.

"RATs such as AlienSpy constitute powerful surveillance tools that would enable them to observe and collect information on the communications and actions of adversaries," Haq says. "As we continue to observe ‘crossover’ in the traditional targeting of state actors and cybercriminals, public and private organizations need to be on alert for phishing and other attacks designed to deliver RATs such as AlienSpy onto client systems."