North Korean Hackers Exploit Unpatched Zimbra Devices in ‘No Pineapple’ Campaign

Feb 02, 2023Ravie LakshmananHealthcare / Cyber Attack

A new intelligence gathering campaign linked to the prolific
North Korean state-sponsored Lazarus Group leveraged known security
flaws in unpatched Zimbra devices to compromise victim systems.

That’s according to Finnish cybersecurity company WithSecure
(formerly F-Secure), which codenamed the incident No
Pineapple.

Targets of the malicious operation included a healthcare
research organization in India, the chemical engineering department
of a leading research university, as well as a manufacturer of
technology used in the energy, research, defense, and healthcare
sectors, suggesting an attempt to breach the supply chain.

Roughly 100GB of data is estimated to have been exported by the
hacking crew following the compromise of an unnamed customer, with
the digital break-in likely taking place in the third quarter of
2022.

“The threat actor gained access to the network by exploiting a
vulnerable Zimbra mail server at the end of August,” WithSecure
said in a detailed technical report^[1] shared with The Hacker
News.

The security flaws used for initial access are CVE-2022-27925 and CVE-2022-37042^[2], both of which could be
abused to gain remote code execution on the underlying server.

This step was succeeded by the installation of web shells and
the exploitation of local privilege escalation vulnerability in the
Zimbra server (i.e., Pwnkit^[3]
aka CVE-2021-4034), thereby enabling the threat actor to harvest
sensitive mailbox data.

Subsequently, in October 2022, the adversary is said to have
carried out lateral movement, reconnaissance, and ultimately
deployed backdoors such as Dtrack and an updated version of
GREASE.

GREASE^[4], which has been
attributed as the handiwork of another North Korea-affiliated
threat cluster called Kimsuky^[5], comes with capabilities^[6]
to create new administrator accounts with remote desktop protocol
(RDP) privileges while also skirting firewall rules.

Dtrack, on the other hand, has been employed in cyber assaults^[7]
aimed at a variety of industry verticals, and also in financially
motivated attacks involving the use of Maui ransomware^[8].

“At the beginning of November, Cobalt Strike
[command-and-control] beacons were detected from an internal server
to two threat actor IP addresses,” researchers Sami Ruohonen and
Stephen Robinson pointed out, adding the data exfiltration occurred
from November 5, 2022, through November 11, 2022.

Also used in the intrusion were tools like Plink and 3Proxy to
create a proxy on the victim system, echoing previous findings^[9]
from Cisco Talos about Lazarus Group’s attacks targeting energy
providers.

North Korea-backed hacking
groups^[10] have had a busy 2022,
conducting both espionage-driven and cryptocurrency heists^[11] that align with the
regime’s strategic priorities.

Most recently, the BlueNoroff cluster, also known by the names
APT38, Copernicium, Stardust Chollima, and Copernicium, and
Stardust Chollima, and TA444, was connected^[12] to wide-ranging
credential harvesting attacks aimed at education, financial,
government, and healthcare sectors.