APT29’s GRAPELOADER Onslaught: New Russian-Backed Phishing Campaign Targets European Diplomats

A Vintage Cyberattack with a Malicious Aftertaste. In April 2025, cybersecurity researchers at Check Point Research (CPR) uncovered a sophisticated phishing campaign targeting European diplomats with fake wine-tasting invitations. The attack, attributed to APT29 (Midnight Blizzard/Cozy Bear), marks the resurgence of this Russian-linked threat group with upgraded malware tools GRAPELOADER and an evolved WINELOADER variant.

This campaign specifically impersonates a European Ministry of Foreign Affairs, luring high-profile targets into downloading malware through seemingly legitimate event invitations. Below, we dissect:

• How the attack unfolds (from phishing emails to backdoor deployment).
• Technical innovations in GRAPELOADER and WINELOADER.
• Why diplomats remain prime targets for APT29.
• 10 actionable defenses against such threats.

Campaign Overview: A Refined Attack with Old Tactics, New Tools

1️. Phishing Lure: The Wine-Tasting Trap

APT29 sent emails from spoofed domains (bakenhof[.]com, silry[.]com) posing as a European foreign affairs official. The emails contained:

• Subject lines: “Wine Event,” “Diplomatic Dinner,” “For Ambassador’s Calendar.”
• Malicious link leading to wine.zip, hosting:
• A legitimate PowerPoint executable (wine.exe) for DLL side-loading.
• A junk-filled DLL (AppvIsvSubsystems64.dll) to evade detection.
• GRAPELOADER (ppcore.dll), a new first-stage backdoor.

Key Insight: The attackers used geofencing—links redirected to the real ministry website unless accessed from specific locations/times.

2️. GRAPELOADER: Stealthier, Smarter, More Evasive

Once executed, GRAPELOADER:

1. Establishes persistence via Windows Registry (SOFTWARE\Microsoft\Windows\CurrentVersion\Run).
2. Fingerprints the victim (username, hostname, process ID).
3. Calls back to C2 (ophibre[.]com) with encrypted HTTPS traffic.
4. Executes next-stage shellcode using advanced anti-analysis tricks:

• Memory manipulation: Shellcode is loaded into PAGE_NOACCESS memory, then switched to PAGE_EXECUTE_READWRITE after a 10-second delay (bypassing EDR scans).
• String obfuscation: Each string uses a unique decryption function, foiling automated tools like FLOSS.

3️. WINELOADER’s Evolution: Harder to Detect, Same Espionage Goals

A new WINELOADER variant (vmtools.dll) was found in related attacks, suggesting GRAPELOADER ultimately delivers it. Key upgrades:

• Better obfuscation: Strings now self-destruct after decryption (unlike older versions).
• Anti-analysis: RWX (Read-Write-Execute) sections, junk exports, and emulation-resistant code.
• C2 communication: Data is RC4-encrypted and sent to bravecup[.]com with a suspicious User-Agent (Windows 7 + Edge 119—a non-existent combo).

Why Diplomats? APT29’s Espionage Playbook

APT29, linked to Russia’s SVR, has long targeted:
✔ Government agencies (e.g., 2020 SolarWinds breach).
✔ Think tanks (e.g., 2016 DNC hack).
✔ Diplomatic entities (e.g., 2024 Indian embassy phishing).

Goals likely include:

• Intelligence gathering (foreign policy insights).
• Access to classified networks via compromised diplomats.
• Long-term persistence in high-value targets.

10 Critical Defenses Against APT29-Style Attacks

1. Train Staff on Advanced Phishing

• Simulate geofenced, event-themed lures (e.g., “VIP dinner invites”).

2. Block Suspicious Domains Preemptively

• Blacklist silry[.]com, bakenhof[.]com, ophibre[.]com, bravecup[.]com.

3. Monitor for DLL Side-Loading

• Flag wine.exe loading AppvIsvSubsystems64.dll.

4. Deploy Memory Protection

• Use EDR solutions to detect PAGE_NOACCESS → PAGE_EXECUTE transitions.

5. Restrict PowerShell & Macro Execution

• APT29 often escalates via scripting.

6. Patch Vulnerable Software

• Especially VMWare Tools (used in WINELOADER side-loading).

7. Analyze Network Anomalies

• Watch for RC4-encrypted HTTPS traffic or fake Edge 119 User-Agents.

8. Enforce Zero Trust for Diplomatic Accounts

• Require MFA for all email/cloud access.

9. Isolate High-Risk Attachments

• Sandbox .zip files claiming to be “event materials.”

10. Share Threat Intel

• Collaborate with DiploSecure or EU’s CERT-EU on APT29 IoCs.

Conclusion: A Persistent Threat with Sharper Claws

APT29’s GRAPELOADER campaign confirms the group’s ongoing focus on European diplomacy and its ability to refine malware faster than defenses adapt. While WINELOADER’s core espionage function remains, its anti-analysis upgrades make it a stealthier, more persistent threat.

Key Takeaways:

• Diplomats = High-value targets: Expect more impersonation of foreign ministries.
• Detection is harder: GRAPELOADER’s memory tricks bypass many EDR tools.
• Proactive defense is critical: Use threat intelligence (like Check Point’s report) to stay ahead.

For real-time protections, Check Point’s Threat Emulation detects this campaign as:

• APT.Wins.WineLoader.A/B
• Trojan.WIN64.WINELOADER variants.

🔗 Reference: Check Point’s Full Report