A China-related threat known as The elusive panda in mid-2023, an unnamed Internet Service Provider (ISP) that pushed malware updates to targeted companies was compromised, highlighting a new level of sophistication associated with the group.
Evasive Panda, also known as Bronze Highland, Daggerfly, and StormBamboo, is a cyberespionage group that has been active since at least 2012, using backdoors such as MgBot (aka POCOSTICK) and Nightdoor (aka NetMM and Suzafk) to collect sensitive information. .
Most recently, there was a threat to the actor formally attributed to the use of a malicious macOS strain called MACMA that was observed in the wild back in 2021.
“StormBamboo is a highly sophisticated and aggressive threat actor that compromises third parties (in this case an ISP) to compromise intended targets,” Volexity said in a report released last week.
“The variety of malware used by this threat actor’s various campaigns indicates a significant effort with active support for payloads not only for macOS and Windows, but also for network devices.”
Public reporting by ESET and Symantec for the past two years documented Evasive Panda’s use of MgBot and its track record of orchestrating attacks on watering holes and supply chains targeting Tibetan users.
It was also established that there is purposeful an international non-governmental organization (NGO) in mainland China with MgBot delivered through legitimate app update channels such as Tencent QQ.
While the Trojan updates were believed to be either the result of a supply chain hack of Tencent QQ’s update servers or a case of an adversary-in-the-middle (AitM) attack, Volexity’s analysis confirms that the latter was the result of a DNS poisoning attack at the ISP level.
Specifically, the threat actor allegedly altered DNS query responses for certain domains associated with automatic software update mechanisms, targeting software that used unsafe update mechanisms such as HTTP or did not provide proper integrity checks on installers.
“StormBamboo was found to have poisoned DNS queries for malware deployment via the HTTP auto-update mechanism and poisoned responses for legitimate hostnames used as second-stage command and control (C2) servers,” researchers Ankur Saini, Paul Rasconieres, Steven Adair and Thomas Lancaster said.
The attack chains are quite simple in that insecure update mechanisms are used to deliver MgBot or MACMA depending on the operating system used. Volexity said it notified the relevant ISP to address the DNS poisoning attack.
One of the cases also involved deploying a Google Chrome extension on the victim’s macOS device by modifying the Secure Preferences file. The browser add-on claims to be a tool that loads a page in Internet Explorer compatibility mode, but its main purpose is to transfer browser cookies to an adversary-controlled Google Drive account.
“An attacker could intercept DNS queries and poison them with malicious IP addresses, and then use this technique to abuse auto-update mechanisms that use HTTP instead of HTTPS,” the researchers said.
