[April 14, 2023] Update: Poland’s Military Counterintelligence Service and CERT have linked APT29 to ongoing and developing attacks against NATO and European Union countries. APT29 collects information from diplomatic entities and foreign ministries through spear-phishing emails and infected websites. The websites infect users with the EnvyScout dropper using HTML smuggling. The dropper installs the SNOWYAMBER and QUARTERRIG downloaders and the HALFRIG CobaltStrike Beacon stager.
Advanced Persistent Threat (APT) groups are widely classified as organizations that lead “attacks on a country’s information assets of national security or strategic economic importance through either cyber espionage or cyber sabotage.” They are elusive, eminent, and influential at what they do: wreaking havoc on their targets. The Cozy Bear group is one of them. In todays’ blog post, we’ll learn more about that group and what this group has done.
A Russian Hacking Organization: Cozy Bear
Cozy Bear is a Russian hacker group allegedly affiliated with one or more Russian intelligence agencies. Mandiant identifies this group as the advanced persistent threat APT29. The group has the advanced capabilities to launch highly targeted attacks like SolarWinds supply-chain attacks where trojanized software updates have been used to infect the MSSP customers.
The Dutch General Intelligence and Security Service (AIVD) inferred from security camera footage that it is led by the Russian Foreign Intelligence Service (SVR); the US agrees. CrowdStrike, a cybersecurity firm, previously speculated that the group might be linked to the Russian Federal Security Service (FSB). CozyCar, CozyDuke (by F-Secure), Dark Halo, The Dukes (by Volexity), NOBELIUM, Office Monkeys, StellarParticle, UNC2452, and YTTRIUM are some of the nicknames given to the group by different cybersecurity research groups.

APT29 Profile Card from SOCRadar Cyber Threat Intelligence
Cozy Bear is a well-resourced, highly dedicated, and structured cyberespionage operation that we believe has been operating for the Russian Federation since at least 2008 to collect intelligence in support of foreign and security policy decision-making,’ according to a 2015 assessment from F-Secure. Cozy Bear has an unusual amount of faith in its ability to keep effectively compromising its targets, as well as in its ability to operate without being detected.
Cyber Attacks Associated with APT29
APT29 and another Russian APT group called APT28 (Fancy Bear) infiltrated the Democratic National Committee’s (DNC) network and caused a data breach, which started in 2015 but was detected in 2016.
ESET investigates Operation Ghost, which is believed to have started in 2013 and affected the Ministry of Foreign Affairs of some European countries. ESET also reports that the group has developed new malware families called the PolyglotDuke, RegDuke, and FatDuke.
Later on, the WellMess malware was observed in attacks against Japanese firms in 2018; however, it was not linked to a specific threat actor then. WellMess was linked to Russia’s APT29 in 2020 when the US, UK, and Canada stated Russian hackers used it in attacks against academic and pharmaceutical research institutes involved in developing the COVID-19 vaccine.
APT29, who are the hackers behind the SolarWinds software supply chain attack and the attacks mentioned above, have continued to look for ways to access enterprise networks by targeting IT and cloud services providers with admin rights on their customers’ systems due to their business connection. In a new report, Microsoft warns that the gang has targeted over 140 cloud service resellers and technology suppliers since May and has succeeded in compromising as many as 14. Moreover, Cozy Bear is the hacker behind the SolarWinds software supply chain attack.
Denmark National Bank has been another victim of the notorious group’s SolarWinds attack. According to a report published in May 2021, Cozy Bear attacked Denmark’s central bank (Denmark’s National Bank) and planted malware that allowed them to access the network for over six months without being noticed.
The SolarWinds campaign is regarded as one of the most sophisticated supply-chain hacks, with 18,000 businesses worldwide downloading trojanized versions of the IT management platform SolarWinds Orion. Despite the hackers’ long-term access, the bank said it found no sign of breach beyond the first stage of the attack, as thousands of other companies did when they installed the trojanized version of SolarWinds Orion.

Attributed attacks to the Russian-speaking hack group Cozy Bear on DarkMirror
In a blog shared by Microsoft Threat Intelligence Center (MSTIC) in 2021, researchers noted that APT29 has been using the EnvyScout, BoomBox, NativeZone, and VaporRage malware families for its email-based attacks since February 2021, which aims to gain a foothold on various sensitive diplomatic and government entities.
In December 2021, ANSSI shared a threat and incident report of the French national government computer security incident response team (CERTFR). The ANSSI stated that French organizations had been subjected to phishing attacks since February 2021, and the identified TTPs overlapped with the SolarWinds supply chain attack.
In April 2022, a lure document that allegedly belonged to APT29 was found, which contained a malicious script and appeared to have been created by the Israeli Embassy.

Malicious lure document allegedly used in APT29 campaign (Source: Inquest)
In January 2022, Crowdstrike shared a blog about a campaign called StellarParticle linked to Cozy Bear. The campaign, conducted with GoldMax and TrailBlazer malware, reveals that since mid-2019, APT29 has used an MFA bypass to access Office 365 accounts with stolen cookies.
Cybersecurity researchers observed that the group uses social media platforms (Twitter, Reddit, etc.) or various internet services (Trello, Firebase, etc.) as C2 (Command & Control) communication during its activities.
In the group’s latest campaign, it was found that they have been using the API of Notion, a note-taking application. Based on the group’s latest campaign details, APT29 used the Polish Foreign Minister‘s recent visit to the US as a lure to conduct a spear phishing campaign targeting Western Countries, particularly Western Europe.
The lure document contains a link to download an HTML file from a legitimate online library the group had actively used in its other attacks between January 2023 to February 2023.
Another observed lure document abuses multiple legitimate systems, such as LegisWrite and eTrustEx, which EU nations use to exchange information and transfer data securely. Using these programs shows that the group targets state organizations within the EU.

You can follow the updates about the latest campaigns of APT29 from the Messy Adventures of Cozy Bear campaign page in SOCRadar LABS.

Malware Used by APT29 / Cozy Bear
The malware used by APT29 could be tailored to the victim’s IT environment by the attackers. Cozy Bear malware’s backdoor components are upgraded over time with cryptography, trojan functionality, and anti-detection changes. The rapidity with which Cozy Bear builds and distributes its components is reminiscent of Fancy Bear’s (APT28) toolkit, including CHOPSTICK and CORESHELL.
Also, some of the malware that APT29 has been observed to use are listed in the table below:
HAMMERTOSS |
SeaDuke |
FatDuke |
CozyCar |
CosmicDuke |
SeaDaddy |
PolyglotDuke |
PinchDuke |
WellMess |
RegDuke |
MiniDuke |
OnionDuke |
SUNBURST |
POSHSPY |
Boombox |
SoreFang |
Critical Vulnerabilities Exploited by APT29 to Gain Initial Foothold
APT29 and its activities are closely monitored by The Cybersecurity and Infrastructure Security Agency (CISA), the Federal Bureau of Investigation (FBI), and the National Security Agency (NSA). In April 2021, CISA released a vital advisory on the critical vulnerabilities exploited by APT29.
The vulnerabilities exploited by the APT29 are listed below:
- CVE-2018-13379 – Fortinet FortiOS
- CVE-2019-9670 – Zimbra Collaboration Suite
- CVE-2019-11510 – Pulse Secure VPN Appliance
- CVE-2019-19781 – Citrix ADC Network Gateway
- CVE-2020-4006 – VMware Workspace ONE Access
- CVE-2022-30170 – Windows Credential Roaming Service Elevation of Privilege Vulnerability.
Defending Against APT Groups
Patch management and other strategies can assist in the defense against APT29 and other similar threats:
- Increase your efforts to identify digital shadow assets, including the cloud hosts, by using an Attack Surface Management solution
- Keep the internet-facing technologies and appliances patched at all times since threat actors continuously scan to detect these blind spots.
- Be wary of external remote services like RDP, which is known to be vulnerable. If not necessary, close it down.
- Quickly take action when you’re alerted by your Threat Intelligence or Digital Risk Protection platform about compromised employee credentials.
- Continuously check for potential weaknesses on your internet infrastructure like expired domains, SSL certificates, or subdomains.
- Keep the password hygiene within the organization at peak condition at all times.
- Make sure EDR and logging functions are in place to detect suspicious actions within the network. It is only one component of the protection plan.