EDR vs Antivirus
Behavioural detection and response versus signature-based blocking.
Antivirus blocks known malware by matching files against signatures of known threats. EDR (endpoint detection and response) records endpoint behaviour to detect, investigate and respond to threats, including novel and fileless attacks that have no signature. Antivirus prevents known bad files; EDR detects and responds to malicious behaviour that antivirus misses.
The short answer
Antivirus blocks known malware by matching files against signatures of known threats. EDR (endpoint detection and response) records endpoint behaviour to detect, investigate and respond to threats, including novel and fileless attacks that have no signature. Antivirus prevents known bad files; EDR detects and responds to malicious behaviour that antivirus misses.
EDR runs an agent on each endpoint that continuously records activity, uses behavioural analysis to detect suspicious sequences of actions, and provides tools to investigate and respond, such as isolating a compromised device.
- Detects behaviour, not just known files
- Catches fileless and novel attacks
- Records a history for investigation
- Enables response, such as endpoint isolation
Traditional antivirus scans files and matches them against a database of known malware signatures, blocking recognised threats. It is efficient against known malware but blind to attacks it has no signature for.
- Blocks known malware efficiently
- Relies on signatures of recognised threats
- Little visibility once something slips through
- Blind to fileless and novel techniques
Key differences
Where EDR and Antivirus diverge, at a glance.
| EDR | Antivirus | |
|---|---|---|
| Detection method | Behavioural analysis | Signature matching |
| Catches novel attacks | Yes | Largely no |
| Visibility | Records full endpoint activity | Minimal beyond file scanning |
| Response | Investigate, isolate, contain | Block or quarantine a file |
| Best against | Modern, evasive attacks | Known malware |
When to choose which
EDR is needed wherever attacks are likely to use novel or fileless techniques, which is now the norm, and where an organisation needs to investigate and respond rather than only block.
Signature-based prevention still has a place as a first filter against the large volume of known, commodity malware, and modern endpoint protection typically includes it alongside EDR.
This is not really a choice between old and new so much as layering prevention and detection. Modern endpoint protection platforms combine signature-based prevention, which cheaply blocks known malware, with EDR, which detects and responds to what prevention misses. Prevention reduces the volume; EDR catches the sophisticated attacks that get through, and both are most effective when operated by a team around the clock.
A worked example: the attack antivirus cannot see
An attacker gains a foothold and, instead of dropping a malware file, uses legitimate tools already present on the system, a technique known as living off the land, to escalate privileges and move through the network. No malicious file is written to disk, so there is no signature for antivirus to match. From the antivirus point of view, nothing bad has happened.
EDR tells a different story. Because it records behaviour rather than only scanning files, it sees the unusual sequence of legitimate tools being chained together in a way that does not fit normal activity, flags it, and lets an analyst investigate and isolate the machine. This is precisely the class of attack, fileless and tool-based, that signature-based antivirus was never designed to catch and that made EDR necessary.
Do modern products combine antivirus and EDR?
In practice, yes. Most modern endpoint security products are platforms that combine next-generation antivirus, which still cheaply blocks the large volume of known malware, with EDR for behavioural detection and response. Microsoft Defender for Endpoint, CrowdStrike Falcon and SentinelOne all pair prevention with detection and response in a single agent.
So the comparison is less about choosing old versus new and more about understanding two layers that now usually ship together. Prevention reduces the volume of threats that reach the detection layer; EDR catches the sophisticated attacks that prevention misses. Buying one without the other leaves a gap in either coverage or efficiency.
Why signatures alone stopped being enough
Antivirus works by matching files against a database of known-bad signatures, which is efficient and effective against recognised malware. The problem is that attackers now routinely recompile malware to change its signature, use fileless techniques that write nothing to disk, and abuse legitimate software, none of which a signature can catch.
This is why endpoint security shifted toward behavioural detection. Rather than asking whether a file matches a known threat, EDR asks whether a sequence of actions looks malicious, which catches novel attacks that have no signature at all. Prevention still has real value against commodity malware, but it can no longer be the only layer.
Not sure which you need?
The right detection stack depends on your environment, your team and your risk. Precursor operates managed detection and response from a CREST-accredited security operations centre, so you get the outcome rather than another tool to run.
EDR vs Antivirus, answered
Common questions about how EDR and Antivirus differ and relate.
EDR extends and largely supersedes traditional standalone antivirus, but modern endpoint protection usually combines both: signature-based prevention as a first filter and EDR for behavioural detection and response. The prevention layer still cheaply blocks known malware.
Antivirus relies on signatures of known threats, and modern attacks increasingly use novel malware, fileless techniques and legitimate tools that have no signature. These pass straight through signature-based scanning, which is why behavioural detection and response became necessary.
Many EDR products are part of a broader endpoint protection platform that includes signature-based prevention, so in practice the two are often delivered together. The behavioural detection of EDR complements, rather than removes, the value of blocking known malware.
EDR extends and largely supersedes traditional standalone antivirus, but modern endpoint protection usually combines both: next-generation antivirus as a first filter that cheaply blocks known malware, and EDR for behavioural detection and response. In most products they ship together rather than one replacing the other.
Antivirus relies on signatures of known threats, and modern attacks increasingly use novel malware, fileless techniques and legitimate tools that have no signature. These pass straight through signature-based scanning, which is why behavioural detection and response became necessary.
Many EDR products are part of a broader endpoint protection platform that includes next-generation antivirus, so the two are often delivered together in a single agent. The behavioural detection of EDR complements, rather than removes, the value of blocking known malware up front.
Both capabilities exist under the Microsoft Defender family. Microsoft Defender Antivirus provides the preventive, signature and next-generation antivirus layer, while Microsoft Defender for Endpoint adds EDR detection and response. In business deployments they work together as prevention plus detection.