​Malware lurks in the South China Sea

There's no smoking gun, but researchers have found evidence that hackers are targeting opponents of China’s claim to the South China Sea.

Organisations involved in the territorial dispute with China over its claim to South China Sea were being targeted with surveillance malware, according to Finnish security firm F-Secure.

Tensions remain high over last month’s ruling by an international tribunal in The Hague that China lacked any legal basis to claim historic rights to the sea and its resources. China rejected the ruling.

According to F-Secure, someone in China was doing their homework during key stages of the arbitration process well ahead of the 12 July decision. The activity crossed into F-Secure’s domain when a remote access trojan (RAT) was distributed and happened to be directed at opponents of China’s sea claim.

The targets of the malware, which F-Secure calls NanHaiShu, included the Department of Justice of the Philippines, organisers of the APEC Summit, which both Barack Obama and Chinese president Xi Jinping attended, and an international law firm that took up the case against China’s claim.

“We believe these entities were targeted for their involvement in a dispute centering on the South China Sea,” said F-Secure.

“Based on the specific selection of organizations targeted for attack by this malware, as well as indications revealed in our technical analysis of the malware itself, we believe the threat actor to be of Chinese origin,” it continued.

The firm grounds its claim on a selection of malware-laden phishing email captured during the two year period of the South China Sea arbitration. The first malware sample in that subset appeared shortly after the Chinese government published position paper on the matter in early December 2014. It's claims were swiftly rejected by the tribunal.

Shorty after this, F-Secure found phishing email with an Excel attachment titled “DOJ Staff bonus January 13, 2015.xls”, which followed a press statement from the arbitration court detailing key deadlines for the respective parties to file arguments in the case.

According to F-Secure, the attackers designed the malware to exploit organisations that allow Microsoft Office macros to execute. Due to a recent resurgence in the use of macro-based malware, Microsoft has urged businesses to ensure macros remain disabled or at least restricted to specific roles and tasks.

The RAT was being spread via targeted phishing email that contained a malicious file attachment. The attachment contains a VBA macro that executes as an embedded Javascript file. Once installed, the RAT steals information from the device and sends it to a remote server.

F-Secure’s efforts to attribute the attack do not go beyond the claim that the attacker is of Chinese origin.