Cranking out spearphishing campaigns towards Ukraine with an developed toolset

ESET Analysis analyzes Gamaredon’s up to date cyberespionage toolset, new stealth-focused methods, and aggressive spearphishing operations noticed all through 2024

02 Jul 2025
 • 
,
6 min. learn

Since Russia’s full-scale invasion of Ukraine in February 2022, cyberespionage has performed a vital function within the broader threatscape. Russia-aligned superior persistent menace (APT) teams have relentlessly focused Ukrainian entities, using cyberattacks alongside disinformation campaigns. ESET Analysis has carefully monitored these actions, recurrently documenting cyber-operations carried out by numerous menace actors, together with the extremely lively Gamaredon group.

Key factors of this blogpost:

• Gamaredon refocused completely on focusing on Ukrainian governmental establishments in 2024, abandoning prior makes an attempt towards NATO international locations.
• The group considerably elevated the size and frequency of spearphishing campaigns, using new supply strategies comparable to malicious hyperlinks and LNK recordsdata executing PowerShell from Cloudflare-hosted domains.
• Gamaredon launched six new malware instruments, leveraging PowerShell and VBScript, designed primarily for stealth, persistence, and lateral motion.
• Current instruments obtained main upgrades, together with enhanced obfuscation, improved stealth techniques, and complex strategies for lateral motion and knowledge exfiltration.
• Gamaredon operators managed to cover nearly their complete C&C infrastructure behind Cloudflare tunnels.
• Gamaredon more and more relied on third-party providers (Telegram, Telegraph, Cloudflare, Dropbox) and DNS-over-HTTPS (DoH) for safeguarding its C&C infrastructure.

In our earlier blogpost, Cyberespionage the Gamaredon manner: Evaluation of toolset used to spy on Ukraine in 2022 and 2023, we described Gamaredon’s aggressive cyberespionage actions towards Ukrainian governmental establishments. As a part of our continued investigation, we’ve performed an intensive technical evaluation of Gamaredon’s operations all through 2024. The detailed outcomes and technical insights can be found in our newest white paper.

Our analysis exhibits that the group stays extremely lively, persistently focusing on Ukraine, however has notably tailored its techniques and instruments.

Concentrating on Ukraine completely

Gamaredon, attributed by the Safety Service of Ukraine (SSU) to the 18th Middle of Data Safety of Russia’s Federal Safety Service (FSB), has focused Ukrainian governmental establishments since at the least 2013. Whereas earlier years noticed occasional makes an attempt towards targets in different NATO international locations, throughout 2024 Gamaredon operators returned their focus completely to Ukrainian establishments.

This strongly aligns with the group’s historic goal as a cyberespionage actor aligned with Russian geopolitical pursuits. Given the continued struggle and geopolitical tensions, we anticipate Gamaredon’s focusing on of Ukraine to proceed unchanged within the foreseeable future.

Spearphishing campaigns develop bigger and extra frequent

Gamaredon’s spearphishing actions considerably intensified in the course of the second half of 2024. Campaigns sometimes lasted one to 5 consecutive days, with emails containing malicious archives (RAR, ZIP, 7z) or XHTML recordsdata using HTML smuggling methods. These recordsdata delivered malicious HTA or LNK recordsdata that executed embedded VBScript downloaders comparable to PteroSand. Determine 1 depicts the variety of distinctive samples of these HTA and LNK recordsdata delivered monthly in Gamaredon spearphishing campaigns in 2024.

Surprisingly, in October 2024, we noticed a uncommon case the place spearphishing emails included malicious hyperlinks slightly than attachments – a deviation from Gamaredon’s normal techniques. Moreover, Gamaredon launched one other novel method: utilizing malicious LNK recordsdata to execute PowerShell instructions straight from Cloudflare-generated domains, bypassing some conventional detection mechanisms.

Toolset evolution: New instruments and important enhancements

Gamaredon’s toolset underwent notable updates. Whereas fewer new instruments had been launched (six in comparison with eight in 2022 and 9 in 2023), substantial sources went into updating and enhancing present instruments:

New instruments launched in 2024 embrace:

• PteroDespair: A brief-lived PowerShell reconnaissance instrument found in January 2024, developed to gather diagnostic knowledge on beforehand deployed malware.
• PteroTickle: A PowerShell weaponizer found in March 2024, focusing on Python purposes transformed into executables on mounted and detachable drives, facilitating lateral motion. It weaponizes Tcl scripts sometimes present in Python GUI apps utilizing Tkinter and constructed with PyInstaller.
• PteroGraphin: Found in August 2024, this PowerShell instrument initially used an unusual persistence methodology involving Microsoft Excel add-ins. It creates an encrypted communication channel for payload supply, by the Telegraph API. Later variations simplified persistence by utilizing scheduled duties as a substitute.
• PteroStew: A brand new general-purpose VBScript downloader found in October 2024, much like beforehand identified downloaders (e.g., PteroSand, PteroRisk), however that notably shops its code in alternate knowledge streams related to benign recordsdata on the sufferer’s system.
• PteroQuark: One other VBScript downloader found in October 2024, launched as a brand new part throughout the VBScript model of the PteroLNK weaponizer.
• PteroBox: A PowerShell file stealer found in November 2024, carefully resembling PteroPSDoor however exfiltrating stolen recordsdata to Dropbox. It leverages WMI occasion subscriptions to detect newly inserted USB drives and exfiltrates chosen recordsdata utilizing the Dropbox API. The stolen recordsdata are meticulously tracked to keep away from redundant uploads, highlighting Gamaredon’s rising consideration to stealth and effectivity.

Main updates to present instruments in 2024

Along with new instruments, Gamaredon operators considerably upgraded present instruments of their arsenal:

• PteroPSDoor: A serious improve launched superior stealth methods, comparable to monitoring file adjustments by way of the IO.FileSystemWatcher object slightly than constantly scanning directories, considerably lowering visibility. It additionally carried out WMI occasion subscriptions to detect new USB insertions, making file exfiltration extra focused and stealthier. Moreover, the most recent variations retailer code completely in registry keys as a substitute of in recordsdata, additional complicating detection.
• PteroLNK (VBScript model): This instrument was enhanced in early 2024 to weaponize not solely USB drives but additionally mapped community drives, increasing its lateral motion capabilities. All through the second half of 2024, it obtained a number of incremental updates, together with improved obfuscation, extra complicated strategies for LNK file creation, and registry-based methods to cover recordsdata and file extensions from victims. This weaponizer has change into one in all Gamaredon’s most steadily up to date and actively maintained instruments.
• PteroVDoor: This VBScript file stealer continued for use in two variants (obfuscated and unobfuscated). All through 2024, Gamaredon operators repeatedly up to date the instrument, introducing new exterior platforms comparable to Codeberg repositories to dynamically distribute command and management (C&C) server data, complicating defensive measures.
• PteroPSLoad: Gamaredon notably transitioned again to utilizing Cloudflare tunnels as a substitute of ngrok for its C&C infrastructure. This marked the start of Gamaredon hiding nearly its complete C&C infrastructure behind Cloudflare-generated domains, considerably enhancing its operational safety.

Uncommon payloads: Russian propaganda by way of malware?

A very intriguing discovering was the invention in July 2024 of a singular advert hoc VBScript payload, delivered by Gamaredon downloaders. This payload had no espionage performance; slightly, its sole function was to robotically open a Telegram propaganda channel named Guardians of Odessa, which spreads pro-Russian messaging focusing on the Odessa area. Whereas uncommon for Gamaredon’s typical operations, we attribute this payload to Gamaredon with excessive confidence.

Community infrastructure and evasion methods

All through 2024, Gamaredon confirmed persistent dedication to evading network-based defenses:

• The group continued, albeit at a diminished scale, to leverage fast-flux DNS methods, steadily rotating IP addresses behind its domains. Nevertheless, the variety of domains that it registered declined notably from over 500 in 2023 to about 200 in 2024.
• Gamaredon more and more relied on third-party providers comparable to Telegram, Telegraph, Codeberg, and Cloudflare tunnels to obfuscate and dynamically distribute its C&C infrastructure. Cloudflare-generated subdomains turned the group’s major communication endpoints, with conventional domains relegated principally to fallback use.
• A number of DoH providers (Google and Cloudflare) and third-party resolver web sites (comparable to nslookup.io, who.is, dnswatch.information, and check-host.internet) had been recurrently leveraged to bypass domain-based blocking.
• Gamaredon additionally launched new methods comparable to dropping embedded HTA and VBScript recordsdata into non permanent directories and executing them individually to resolve C&C domains, additional complicating automated detection efforts.

Regardless of observable capability limitations and abandoning older instruments, Gamaredon stays a major menace actor as a consequence of its steady innovation, aggressive spearphishing campaigns, and protracted efforts to evade detections. So long as the Russia’s struggle towards Ukraine continues, we anticipate Gamaredon will persistently evolve its techniques and intensify its cyberespionage operations towards Ukrainian establishments.

For an in depth technical breakdown of Gamaredon’s 2024 actions, updates, and malware analyses, learn our full white paper.

A complete checklist of indicators of compromise (IoCs) may be present in our GitHub repository and the Gamaredon white paper.

For any inquiries about our analysis printed on WeLiveSecurity, please contact us at threatintel@eset.com. 

ESET Analysis provides non-public APT intelligence stories and knowledge feeds. For any inquiries about this service, go to the ESET Menace Intelligence web page.