Why SIEM Can’t See and Stop Modern Attacks

The SIEM Security Gap

SIEMs are a cornerstone of security operations, but their effectiveness is only as strong as the data they ingest. Without integrated signal from network, cloud, SaaS, and identity layers, and with blind spots across hybrid infrastructure, your SIEM can’t detect what it doesn’t see—leaving your SOC with an incomplete and delayed picture of the attack.

How attackers evade SIEM:  

1. Log blind spots

SIEMs rely on logs, but attackers disable logging, use unmanaged devices, or move through network traffic that isn’t captured.

2. Rule & signature limitations

Threat actors bypass static rules by using living-off-the-land (LotL) techniques and modifying attack patterns.

3. Alert overload & delays

SIEMs generate massive alert volumes with high false positives, delaying detection and response to real threats.

Logs Aren’t Enough—You Need AI Detection, Investigation, and Response

SIEM alone isn’t enough to detect advanced threats because it relies on log collection and correlation rules rather than real-time behavioral detection. Security teams need an approach that goes beyond logs and alerts to detect threats as they happen.

SIEMs collect and analyze security logs, but:

• What if an attacker disables or avoids logging? Many threats never generate logs, leaving SIEM blind to them.

• What if the attack doesn’t match known patterns? SIEM rules rely on predefined signatures, missing novel or evolving threats.

• What if there’s too much noise? Analysts are overwhelmed with alerts, slowing down response times.

How Vectra AI Fills the Gap

SIEM alone can’t stop modern attacks that move beyond log-based detection. The Vectra AI Platform provides real-time threat visibility across network, cloud, and identity layers, closing the gaps SIEM leaves behind. Here’s how:

• Detects attacks beyond logs – AI analyzes live network and identity behavior to expose threats that never generate logs.

• Prioritizes real threats – Cuts through SIEM alert noise by surfacing high-confidence detections of active attacks.

• Enhances SIEM & XDR – Works alongside SIEM to provide deeper detection and faster response.

With Vectra AI, you can detect threats in real time—before they escalate into breaches.

How Vectra AI Complements SIEM

SIEMs rely on logs, while Vectra AI provides live threat detection across network, cloud, and identity layers. Here’s how they compare:

Vectra AI doesn’t replace SIEM—it enhances it by detecting the threats that logs miss.