Malware Used by China APT Group Abuses Dropbox

Attacks launched in August by a Chinese APT group against media organizations based in Hong Kong leveraged a piece of malware that abused Dropbox for command and control (C&C) communications, FireEye reported on Tuesday.

The security firm believes the cyber espionage campaign could be the work of a group identified as [email protected]. The APT actor, active since 2008, has been seen targeting organizations in the financial services, telecoms, government, and defense sectors.

In August 2013, FireEye reported that [email protected] had been using the Poison Ivy RAT in its operations. In March 2014, the group leveraged the disappearance of Malaysia Airlines Flight MH370 to target a government in the Asia-Pacific region and a US-based think tank.

The same group is suspected of launching a spear phishing campaign in August against media organizations in Hong Kong. According to FireEye, the attackers sent out emails containing malicious documents designed to exploit Microsoft Office vulnerabilities in an effort to deliver a piece of malware dubbed “LOWBALL.”

Once it infects a system, the LOWBALL backdoor uses the API provided by cloud storage service Dropbox for C&C communications. The malware allows attackers to collect information about the compromised device and the network it belongs to, which can be useful for further attacks.

The threat group’s Dropbox accounts have also been found to contain a different backdoor dubbed “BUBBLEWRAP.” This piece of malware, known to be used by [email protected] in the past, is a full-featured backdoor that collects information on the compromised host. It can also use various plugins to enhance its capabilities.

The recent attacks against Hong Kong newspapers, radio and TV stations coincided with charges brought against three Hong Kong students that were part of the 2014 pro-democracy movement.

Researchers have pointed out that it’s not uncommon for China-based threat groups to target Hong Kong media organizations, particularly ones whose reporting focuses on the pro-democracy movement. The August campaign was aimed at organizations holding information that could be of value to the Chinese government.

“Cyber threat groups’ access to the media organization’s networks could potentially provide the government advance warning on upcoming protests, information on pro-democracy group leaders, and insights needed to disrupt activity on the Internet, such as what occurred in mid-2014 when several websites were brought down in denial of service attacks,” FireEye said in a blog post.

While working with Dropbox to analyze the attacks aimed at Hong Kong media companies, FireEye discovered a second operation that might be conducted by [email protected], although experts say they lack conclusive evidence. The security firm has not been able to identify the victims of this second campaign.

“The attack lifecycle followed the same pattern, though some of the filenames were different, which indicates that there may be multiple versions of the malware. In addition, while the operation targeting Hong Kong-based media involved a smaller number of targets and a limited duration, we suspect this second operation involves up to 50 targets,” experts said.

Related Reading: China Cybergang Using Hacking Team Exploits Against Financial Firm

Related Reading: Naikon Threat Group Linked to Chinese Army