APT29 Hackers Use GRAPELOADER in New Attack Against European Diplomats

Check Point Research (CPR) has uncovered a new targeted phishing campaign employing GRAPELOADER, a sophisticated initial-stage downloader, launched by the notorious Russian-linked hacking group APT29, known alternatively as Midnight Blizzard or Cozy Bear.

This campaign, identified since January 2025, primarily focuses on European governments and diplomatic entities.

Campaign Overview

APT29, recognized for its sophisticated cyber operations against high-profile organizations, has pivoted back to its known approach of using themed phishing emails to initiate infections.

Approximately one year after their last campaign involving WINELOADER, the group has adopted GRAPELOADER, a tool designed for environment fingerprinting, establishing persistence, and payload delivery, to infiltrate systems of diplomats and government officials in Europe.

The campaign begins with carefully crafted phishing emails masquerading as invitations from the Ministry of Foreign Affairs of a European country, enticing recipients to join exclusive wine-tasting events.

These emails are sent from domains bakenhof[.]com and silry[.]com, with subjects like “Wine Event,” “Wine Testing Event,” and “For Ambassador’s Calendar.”

According to the Report, the emails contain a link leading to the download of an archive named ‘wine.zip,’ initiating the infection process.

Technical Analysis

GRAPELOADER:

• Delivery Method: GRAPELOADER is embedded within a 64-bit DLL (ppcore.dll) inside the ‘wine.zip’ archive, alongside a legitimate PowerPoint executable (wine.exe) for DLL side-loading, and a bloated DLL (AppvIsvSubsystems64.dll) as a required dependency.
• Persistence: It secures persistence by modifying the Windows registry’s Run key to execute wine.exe automatically upon system startup, copying files to %APPDATA%\Local\POWERPNT\.
• C2 Communication: GRAPELOADER communicates with its C2 server at hxxps://ophibre[.]com/blog.php using an HTTPS POST request, submitting collected environment information, including UserName, ComputerName, and others. The request uses a User-Agent string mimicking a legitimate browser.

• Shellcode Execution & Evasion: GRAPELOADER employs an evasion technique where it allocates memory, changes its protection to PAGE_NOACCESS, and then starts a new thread to execute shellcode without writing it to disk, thus evading detection by AV/EDR solutions.

WINELOADER:

A new variant of WINELOADER (vmtools.dll) was discovered in close proximity to GRAPELOADER infections, indicating its use in later stages of the attack. Key characteristics include:

• Unpacking Routine: Similar to previous versions, WINELOADER uses an unpacking routine, decrypting its core module with RC4 and using the same algorithm for string decryption and C2 communication.
• C2 Communication: WINELOADER sends an encrypted structure containing system information to the C2 server at hxxps://bravecup[.]com/view.php, using a deliberate mismatch between the Windows version and the browser User-Agent string for further obfuscation.
• Evolving Techniques: The new WINELOADER variant showcases enhancements in string decryption, anti-analysis techniques, and persistence, suggesting continuous evolution in APT29’s toolkit.

The similarities in TTPs, from the themed phishing emails to the use of DLL side-loading, fingerprinting, and the structural resemblances between GRAPELOADER and WINELOADER, strongly indicate that this campaign is another part of APT29’s strategy to compromise sensitive targets.

The shift to GRAPELOADER as an initial stager further demonstrates their adaptability in evading detection and analysis tools.

Check Point’s Threat Emulation and Harmony Endpoint solutions provide comprehensive protection against these threats by recognizing and neutralizing the attack vectors described, effectively safeguarding against these sophisticated attacks.

The cybersecurity community continues to monitor APT29’s operations, urging organizations, especially those in diplomacy, to maintain robust security practices to mitigate such advanced persistent threats.

Indicators of Compromise (IOCs):

File/Domain	SHA256 Hash
wine.zip	653db3b63bb0e8c2db675cd047b737cefebb1c955bd99e7a93899e2144d34358
wine.exe	420d20cddfaada4e96824a9184ac695800764961bad7654a6a6c3fe9b1b74b9a
AppvIsvSubsystems64.dll	d931078b63d94726d4be5dc1a00324275b53b935b77d3eed1712461f0c180164, 24c079b24851a5cc8f61565176bbf1157b9d5559c642e31139ab8d76bbb320f8
vmtools.dll	adfe0ef4ef181c4b19437100153e9fe7aed119f5049e5489a36692757460b9f8
Domain	bakenhof[.]com, silry[.]com, ophibre[.]com, bravecup[.]com

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