Advanced Persistent Threat (APT) groups are often associated with zero-day exploits and custom-built malware frameworks. However, the latest campaign attributed to APT28 demonstrates that modern nation-state operations do not always require technical complexity to be effective.
According to reporting from The Hacker News, the Russia-linked threat actor conducted a campaign dubbed Operation MacroMaze, targeting specific organizations across Western and Central Europe between September 2025 and January 2026. The operation relied on macro-enabled Microsoft Office documents and publicly available webhook services to establish access and facilitate data exfiltration.
This campaign reflects a strategic shift toward low-footprint, infrastructure-abuse techniques designed to evade detection by blending into legitimate enterprise activity.
The intrusion begins with spear-phishing emails delivering carefully crafted Microsoft Office documents. Embedded within the document structure is an XML field named INCLUDEPICTURE that references a webhook[.]site URL hosting an image file. When the recipient opens the document, Microsoft Word automatically retrieves the image from the remote server, triggering an outbound HTTP request.
This request serves as a beacon, allowing the attacker to confirm that the document was opened and to log associated metadata. While this initial step appears benign, it enables the attacker to validate access before progressing further.
Subsequent stages involve macro execution that launches a VBScript. The script runs a command file that establishes persistence through scheduled tasks. A batch file then renders a Base64-encoded HTML payload within Microsoft Edge. In earlier variants of the campaign, Edge is executed in headless mode. In later versions, the browser window is moved off-screen while other Edge processes are terminated to maintain execution control.
The HTML payload retrieves commands from a webhook endpoint, executes them locally, captures the output, and transmits the results back to another webhook instance through standard form submission. By leveraging legitimate browser functionality and encrypted web traffic, the attackers minimize detectable artifacts on disk while maintaining command-and-control capability.
Operation MacroMaze illustrates how modern intrusion chains are intentionally constructed to avoid triggering isolated security controls. Each stage of the attack uses legitimate tools and approved system processes.
Document execution, browser activity, scheduled task creation, and encrypted outbound HTTPS communication are common within enterprise environments. When analyzed independently, these activities may not appear suspicious.
The risk emerges when these events are correlated over time. Without unified visibility across identity systems, endpoints, and network telemetry, early indicators of compromise remain fragmented. Email gateways may see a benign attachment. Endpoint tools may not flag lightweight scripts. Network monitoring may observe encrypted traffic to a legitimate domain. Identity systems may record valid credential usage.
By the time a meaningful pattern is detected, persistence may already be established and sensitive information may have been exfiltrated. For European organizations operating in regulated sectors or strategic industries, this delay significantly increases operational and geopolitical exposure.
The APT28 campaign highlights a broader evolution in nation-state tradecraft. Rather than investing in complex malware frameworks for every operation, adversaries are increasingly abusing trusted infrastructure and built-in system functionality.
This approach reduces the attacker’s operational overhead while increasing defender complexity. It also shifts the burden of detection from signature-based analysis to behavioral correlation.
Traditional security models focused on identifying known malicious files or domains struggle against campaigns that rely on legitimate services and minimal disk artifacts. As a result, prevention must focus on identifying abnormal behavior patterns rather than isolated technical indicators.
Stopping campaigns like Operation MacroMaze requires continuous correlation across identity, endpoint, network, and cloud environments. Seceon’s unified SIEM and XDR platform is designed to provide that integrated visibility.
In a scenario similar to this campaign, Seceon would detect anomalous outbound webhook communication that occurs immediately after document execution. It would correlate suspicious scheduled task creation with Office macro activity and identify unusual Microsoft Edge instances operating in non-interactive contexts. Script-based persistence combined with external command retrieval would be analyzed as part of a larger behavioral sequence rather than as isolated events.
Because Seceon continuously correlates telemetry across multiple layers of the environment, the attack chain can be surfaced during reconnaissance and persistence phases, before sustained exfiltration occurs. Automated response workflows can then isolate affected systems and disrupt command-and-control communication.
Additionally, continuous validation capabilities enable security teams to simulate macro-based and webhook-driven intrusion paths, ensuring detection logic remains effective as adversary techniques evolve.
APT28’s targeting of European entities using webhook-based macro malware underscores a significant shift in modern threat operations. Advanced campaigns are increasingly defined not by complexity, but by precision and stealth.
By leveraging legitimate tools and infrastructure, nation-state actors can conduct effective espionage while minimizing traditional indicators of compromise. For organizations across Europe and beyond, the challenge is no longer simply blocking malicious files. It is recognizing when normal system behavior begins to align with adversary intent.
Effective defense requires unified visibility, behavioral analytics, and automated response capabilities that operate across the full attack lifecycle. In a landscape where trusted services can be weaponized, early correlation becomes the decisive factor between contained intrusion and strategic compromise.
