DPRK fund malicious cyber activities with ransomware attacks on critical Infrastructure
Vulnerabilities mentionedAll →
| CVE | Vulnerability | CVSS | EPSS | Flags | Affected | Exposure | Published |
|---|---|---|---|---|---|---|---|
| CVE-2021-20038 | Unauthenticated Stack Buffer Overflow in SonicWall SMA 100 Appliances SonicWall SMA 100 series secure remote-access appliances contain an unauthenticated stack-based buffer overflow (CWE-121) in the appliance's network-facing interface, triggered by crafted requests sent to the device without any credentials. A remote attacker who triggers the overflow can execute arbitrary code on the appliance with the privileges of the affected service, gaining a foothold on an internet-facing VPN gateway that typically sits at the network edge. Any organization running an SMA 100 series appliance is affected, and because these appliances provide remote access to corporate networks, compromise can expose entire internal environments. Exploitation is confirmed in the wild: the flaw was added to CISA KEV on 2022-01-28 with known ransomware use, and EPSS assigns a 99.9% probability of exploitation within 30 days (100th percentile). No public proof-of-concept is catalogued in the provided data, but the KEV listing and EPSS score indicate active attacker interest. Do: Upgrade SMA 100 series appliances to firmware 10.0.7.2 or later per SonicWall's instructions, as required by the CISA KEV listing. Until patched, restrict internet exposure of the SMA portal and management interface to trusted sources where feasible. Because ransomware operators are known to exploit this flaw, review appliance logs for signs of compromise and monitor for unexpected account creation or traffic after patching. | 9.8 | 100% | KEV ransomware PoC ×2 |
| largetens of thousands of internet-exposed SMA 100 appliances (order of magnitude ~10,000-50,000 devices), plus a larger installed base used internally | |
| CVE-2022-24990 | Unauthenticated RCE via Admin Password Leak in TerraMaster TOS 4.2.29 and earlier TerraMaster TOS (TerraMaster OS) versions 4.2.29 and earlier do not require authentication (CWE-306) on the mobile API endpoint module/api.php?mobile/webNasIPS, and a request presenting the User-Agent "TNAS" returns system information that includes the administrative account's password in the PWD field. An unauthenticated attacker with network access to the NAS web interface can send this request and read the response, obtaining full administrative credentials. With those credentials an attacker controls the NAS, and public proof-of-concept exploits chain this flaw with a PHP object-instantiation bug to achieve unauthenticated remote command execution. Any TerraMaster NAS running TOS 4.2.29 or earlier is affected, with internet-exposed devices at the greatest risk. Exploitation is confirmed: the flaw is in CISA's Known Exploited Vulnerabilities Catalog (added 2023-02-10) with known ransomware use, carries an EPSS of roughly 84%, and CISA and press reports describe active attacks, including North Korean ransomware activity against healthcare and critical infrastructure. Do: Upgrade TerraMaster TOS to a release newer than 4.2.29 per the vendor's instructions, as required by the CISA KEV entry. If patching must wait, restrict the TOS web interface to trusted networks so unauthenticated users cannot reach module/api.php?mobile/webNasIPS. Check device logs for requests to the webNasIPS endpoint with a TNAS User-Agent and look for signs of post-compromise activity, since ransomware use of this flaw is known. | 7.5 | 84% | KEV ransomware PoC ×3 |
| largeon the order of tens of thousands of internet-exposed TerraMaster NAS devices (estimate, not a verified count) |
Full article596 words · extracted from securityaffairs.com · click to collapse
Pierluigi Paganini
February 10, 2023
North Korea-linked APT groups conduct ransomware attacks against healthcare and critical infrastructure facilities to fund its activities.
Ransomware attacks on critical infrastructure conducted by North Korea-linked hacker groups are used by the government of Pyongyang to fund its malicious cyber operations, U.S. and South Korean agencies warn.
US CISA published a Cybersecurity Advisory (CSA) to provide information about the threat actors to network defenders. The joint CSA about ongoing ransomware activity against Healthcare and Public Health Sector organizations and other critical infrastructure sector entities is the result of the collaboration between the United States National Security Agency (NSA), the U.S. Federal Bureau of Investigation (FBI), the U.S. Cybersecurity and Infrastructure Security Agency (CISA), the U.S. Department of Health and Human Services (HHS), the Republic of Korea (ROK) National Intelligence Service (NIS), and the ROK Defense Security Agency (DSA) (hereafter referred to as the “authoring agencies”).
“This advisory highlights TTPs and IOCs DPRK cyber actors used to gain access to and conduct ransomware attacks against Healthcare and Public Health (HPH) Sector organizations and other critical infrastructure sector entities, as well as DPRK cyber actors’ use of cryptocurrency to demand ransoms.” reads the joint advisory.
The proceeds from ransom payments are used by the North Korean government to fund malicious activities, including cyber operations against the United States and South Korea.
The list of targets includes Department of Defense Information Networks and Defense Industrial Base member networks.
Some of the ransomware families attributed to North Korea-linked APT groups are Maui, Holy Ghost, and VHD.
The government agencies detailed TTPs associated with North Korean APT groups such as:
- Acquire Infrastructure [T1583]. Threat actors generate domains, personas, and accounts; and identify cryptocurrency services to conduct their ransomware operations.
- Obfuscate Identity. Threat actors purposely obfuscate their involvement by operating with or under third-party foreign affiliate identities and use third-party foreign intermediaries to receive ransom payments.
- Purchase VPNs and VPSs [T1583.003]. threat actors use virtual private networks (VPNs) and virtual private servers (VPSs) or third-country IP addresses to hide the origin of the attacks.
- Gain Access [TA0001]. Threat actors use various exploits of common vulnerabilities, including CVE 2021-44228, CVE-2021-20038, and CVE-2022-24990. The advisory also states that the attackers employed Trojanized files for “X-Popup,” an open source messenger commonly used by employees of small and medium hospitals in South Korea, in their attacks.
- Move Laterally and Discovery [TA0007, TA0008]. Attackers use staged payloads with customized malware to perform reconnaissance activities, upload and download additional files and executables, and execute shell commands [T1083, T1021]. The malware is also used for collecting victim information and sending it to the remote host [TA0010].
- Employ Various Ransomware Tools [TA0040]. Attackers used privately developed ransomware, such as Maui and H0lyGh0st along with other ransomware families, including BitLocker, Deadbolt, ech0raix, GonnaCry, Hidden Tear, Jigsaw, LockBit 2.0, My Little Ransomware, NxRansomware, Ryuk, and YourRansom [T1486].
- Demand Ransom in Cryptocurrency. Nation state actors demanded ransom payments in bitcoin [T1486]. They communicate with victims via Proton Mail email accounts.
The agencies recommend organizations to limit access to data by authenticating and encrypting connections, implement the principle of least privilege, turn off weak or unnecessary network device management interfaces, enforce multi-layer network segmentation, protect stored data, require phishing-resistant authentication controls, use monitoring tools, and maintain periodic data backups.
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(SecurityAffairs – hacking, North Korea-linked APT)
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