Multistage attacks combine phishing, vulnerability exploitation, and advanced evasion techniques to silently and progressively compromise corporate networks.
Unlike isolated attacks, they act as well-structured campaigns, built step by step to ensure access, internal movement, and execution of critical actions within the environment.
The challenge is that the more steps there are in the chain, the more difficult it becomes to identify what is happening. In many incidents, the security team only notices the attack when the damage has already been done.
Data is exfiltrated, backups are removed, and entire systems are encrypted by ransomware operators or groups specializing in espionage.
In this blog, you will learn in detail how these attacks work, why they are so difficult to detect, and how frameworks such as CKC and MITRE ATT&CK help map each move of the adversary, providing clarity to interrupt the chain as early as possible.
What are multistage attacks in practice?
A multistage attack is a sequence of interconnected actions. Each phase sets the stage for the next, creating a continuous flow from initial access to financial gain or sabotage.
Unlike isolated attacks, which rely on a single exploit or specific malware, multistage attacks use tactics, techniques, and procedures that evolve as the attacker advances within the environment.
This is the preferred method of advanced groups, such as human-assisted ransomware operators and agents specializing in digital espionage.
In addition, multistage attacks have become increasingly accessible, as attack kits, exploits, and automated services can be purchased on the digital underground by any criminal.
Why is this type of attack growing so much?
The answer is simple: because it works. Recent research shows that the average time to initial compromise is only 48 minutes, and can be even shorter in vulnerable environments.
There are cases where initial access occurs in less than a minute. At this rate, relying solely on manual analysis or human checks is not enough.
Defenses need to be able to correlate events in milliseconds, identify non-standard behavior, and block the attack chain before it advances.
At the same time, advanced tools that were once restricted to governments and large groups can now be purchased as a service, which lowers the barrier to entry for less experienced criminals.
How do Multistage Attacks work?
To understand the adversary’s progression, two models complement each other and help security teams analyze the attack chain.
- Cyber Kill Chain: provides a strategic view, showing the macro path of the attack from initial reconnaissance to final action. It helps to understand where the attack is, but has limitations because it assumes a fixed line of progression.
- MITRE ATT&CK: provides the tactical level, with real techniques used in the field. It details how the attacker executes each step, explaining everything from initial access methods to persistence, evasion, command, and control techniques.
Overall, both models work best when used together: CKC to see the journey and MITRE to understand each specific movement of the adversary.
What are the stages of a multistage attack?
Below, we present a realistic flow of a common attack involving phishing, malware, and lateral movement, characteristic of human-operated ransomware campaigns.
Initial access
The attack usually begins with phishing, exploiting vulnerabilities in VPNs, exposed ports, or flaws in remote services. The goal is to obtain valid credentials or privileged access to some point in the environment.
All it takes is a single user revealing their password or a misconfigured service for the attacker to have the entry point they need.
Internal recognition
With access secured, the attacker begins mapping the network. They identify machines, servers, user groups, domain controllers, and paths to get closer to critical assets.
The problem is that, at this stage, almost nothing looks malicious. Native system tools are used, such as PowerShell, WMI, and legitimate scanners. This is why signature-based detection alone fails.
Credential collection and lateral movement
With the network mapped, the attacker searches for privileged credentials using tools such as Mimikatz, memory hash collection, or exploitation of passwords stored in files.
Then, they move laterally across the network using RDP, SMB, PsExec, or any protocol already present in the environment. It is at this point that they begin to reach critical servers and sensitive assets.
Evasion and persistence
Before performing any destructive actions, the attacker must ensure that they can operate without being detected.
They disable antivirus software, manipulate firewall rules, and create persistence mechanisms. They may also use techniques such as Sticky Keys hacking or the abuse of legitimate Windows binaries.
This step is one of the most difficult to identify without deep telemetry and behavioral analysis.
Final action
With the environment fully compromised, the attacker executes their ultimate goal. In modern campaigns, this includes data exfiltration, backup removal, service shutdown, and simultaneous ransomware deployment.
Data theft almost always precedes encryption, creating a double extortion model that increases the financial and operational impact.
Why are multistage attacks so difficult to detect?
There are three main pillars that make multistage attacks particularly challenging.
The first is Living Off The Land, when the attacker uses legitimate tools for malicious actions. As a result, most activities are camouflaged among common operations and go unnoticed.
The second pillar is the evasion of sandboxes and traditional detection mechanisms, as modern malware behaves harmlessly when it detects an analysis environment.
The third pillar is the industrialization of digital crime, driven by ready-made services, specialized kits, and technical support that make any attack more efficient.
How to defend yourself?
Multistage attacks are smarter, quieter, and more agile. They work in layers, evolve quietly, and infiltrate corporate environments for weeks or months without triggering traditional alerts.
To combat them, it is not enough to use individual tools. Defense must be coordinated, correlated, and behavior-driven. Therefore, invest in:
- XDR with behavioral analysis to detect anomalous actions and identify patterns that indicate the attack chain.
- Continuous monitoring of Active Directory, including tracking suspicious changes and replication traffic.
- Least privilege policies, reducing the impact if credentials are compromised.
- Advanced endpoint, network, and identity telemetry to observe lateral movements and evasion attempts.
- MFA and Zero Trust-based access controls, ensuring that each request is validated and contextualized.
- Event correlation, essential for connecting small actions that, in isolation, do not appear to be an attack, but together reveal the complete chain.
The sooner the chain is interrupted, the less the impact. In a scenario where initial access can occur in seconds, these solutions become minimum requirements for maintaining secure operations.
