In early September 2025, threat intelligence firms announced the emergence of a new malware strain colloquially referred to as DeepLoad. Unlike conventional ransomware or cryptojacking tools, DeepLoad’s primary objective is the surreptitious extraction of stored browser credentials, turning everyday login data into a high‑value intelligence target. What sets this campaign apart is the sophisticated chain of legitimate‑looking tooling it employs: the ClickFix loader for rapid, file‑less execution, and Windows Management Instrumentation (WMI) for durable, stealthy persistence. By leveraging these techniques, the attackers can operate entirely in memory, evade signature‑based detection, and exfiltrate credentials without ever writing a malicious file to disk. This shift toward memory‑resident, credential‑focused attacks signals a broader trend in which adversaries prioritize low‑profile tactics that maximize operational longevity and minimize forensic footprints.
Understanding the ClickFix Mechanism
ClickFix is a lightweight, in‑memory loader that has been observed in a variety of recent campaigns targeting Windows environments. Its core design principle is to hijack a legitimate Windows API call sequence that briefly grants elevated privileges, allowing the payload to be injected into an already running process. Because ClickFix never writes an executable to the file system, traditional antivirus products that rely on disk scanning are completely blind to its presence. The loader’s execution window is often measured in milliseconds, which further reduces the chance that behavioral heuristics will flag the activity. Key characteristics of ClickFix include:
- Use of
CreateProcesswith a suspended state to inject code into a trusted host. - Rapid decryption of embedded payload sections directly in memory.
- Dynamic resolution of required Windows APIs at runtime, preventing static analysis.
By staying resident only in memory, ClickFix enables the subsequent stages of the attack to proceed without leaving traces that could be detected by conventional endpoint protection tools.
Exploiting WMI for Persistence
Windows Management Instrumentation (WMI) is a built‑in system management framework that provides administrators with powerful remote execution capabilities. Unfortunately, its legitimate uses also make it an attractive vector for attackers seeking persistent execution channels. In the DeepLoad campaign, the malware creates a WMI Event Subscription that triggers a PowerShell command whenever a specific WMI event fires — commonly associated with system startup or user logon. The persistence is typically registered using the __EventFilter and __Namespace classes, ensuring that the malicious payload is relaunched automatically after reboots or user sessions.
The creation of such a filter can be expressed in a compact WMI query, for example:
SELECT * FROM __EventFilter WITH (EventName = 'DeepLoad_Start')When the filter detects the specified event, it invokes the associated command line, which typically launches a PowerShell process that loads the ClickFix payload from memory. Because WMI operations are signed and trusted by the operating system, activity of this nature often bypasses naïve monitoring solutions that focus on executable file creation.
Why this matters: WMI‑based persistence allows the attacker to survive system reboots, maintain access across user sessions, and blend in with legitimate administrative traffic, making detection extremely challenging without deep visibility into WMI event logs.
Credential Harvesting from Browser Stores
One of the most damaging capabilities of DeepLoad is its ability to extract saved credentials from a wide range of web browsers, including Google Chrome, Microsoft Edge, and Mozilla Firefox. Browsers store login information in encrypted SQLite databases located within the user profile directory. While these databases are protected by OS‑level permissions and, in many cases, by a master key stored in the Windows Credential Manager, malware with sufficient privileges can read them directly from memory or from the on‑disk files.
DeepLoad achieves credential extraction by injecting a malicious DLL into the browser process itself. Once injected, the DLL enumerates the Login Data and Web Data tables, decrypts entries using the keys stored in the Credential Manager, and bundles the harvested credentials into a compressed payload for exfiltration. The exfiltration channel typically leverages an HTTPS POST request to a command‑and‑control (C2) server, where the data is encoded to evade network‑based detection.
Implications for organizations: Stolen credentials can be used for credential stuffing, lateral movement, or direct access to corporate accounts, leading to data breaches, ransomware deployment, or insider threat scenarios. Because the theft occurs within the browser process, traditional endpoint detection mechanisms that focus on file‑system anomalies may never see the malicious activity.
Practical Mitigation Checklist
To defend against a DeepLoad‑style attack, organizations should adopt a layered set of controls that address each stage of the attack chain. The following checklist provides actionable steps for both IT administrators and business leaders:
- Enforce Application Control Policies: Deploy Windows Defender Application Control (WDAC) or similar whitelisting solutions to block unsigned binaries and restrict execution of PowerShell scripts to known, approved paths.
- Restrict WMI Creation Rights: Use Group Policy Objects (GPOs) to limit which security principals can create event filters, consumers, or providers; enable detailed WMI activity logging and forward logs to a SIEM for analysis.
- Enable Advanced PowerShell Logging: Turn on Script Block Logging, Module Logging, and Transcription to capture PowerShell commands as they execute, even when they run from memory.
- Harden Browser Credential Management: Implement enterprise policies that disable automatic password saving, enforce expiration of saved credentials, and promote the use of password managers that encrypt data outside the browser profile.
- Deploy Memory‑Resident Detection Tools: Utilize EDR solutions capable of monitoring for anomalous DLL injections, unusual process hollowing, and unexpected WMI event registration patterns.
- Network Segmentation and Traffic Filtering: Isolate systems that store sensitive credentials from the broader corporate network, and apply TLS inspection or proxy logging to detect anomalous outbound POST requests to unknown endpoints.
- Regular Patch Management and Configuration Hygiene: Keep Windows, browsers, and third‑party applications up to date, and audit WMI namespace permissions for orphaned event filters or providers that may have been left behind by previous incidents.
- Incident Response Readiness: Maintain a playbook that includes memory forensics procedures, credential revocation processes, and communication protocols for notifying stakeholders in the event of a breach.
Implementing these controls not only reduces the likelihood of successful infection but also shortens the window of detection if a breach does occur.
Conclusion
The DeepLoad malware exemplifies the next generation of threat actors who combine file‑less loading techniques with trusted system services to achieve stealthy, credential‑focused objectives. By leveraging ClickFix for rapid execution and WMI for durable persistence, the attackers can operate entirely in memory, exfiltrate valuable browser credentials, and evade many traditional security controls. For modern enterprises, the lesson is clear: defensive strategies must evolve beyond signature‑based detection to encompass memory‑level monitoring, robust WMI governance, and proactive credential hygiene. Investing in professional IT management and advanced security services ensures that organizations benefit from expert oversight, continuous threat intelligence, and a coordinated response posture. In an environment where attackers can silently harvest credentials without ever touching the file system, the strategic value of a mature, holistic security framework cannot be overstated.