7 Early Warning Signals before a Cyberattack: Know what to look for and how to counter them

February 26, 2026

Cyberattacks rarely occur on impact. There are often early warning signals.

Long before ransomware detonates, credentials are stolen and sold, meaning data is quietly being exfiltrated from the system. Meaning there are indicators. Slight behavior shifts. Fragments of telemetry that, viewed individually, look harmless. Viewed as a collective, they tell a story.

Most organizations do not fall victim because they lack tools. They become victims because they lose or dismiss early warning signals as noise.

If you want to interrupt an attack before it becomes an incident, you have to know what to look for and you have to treat weak signals seriously.

1. Identity Anomalies that Do Not Make Sense

Identity is the primary control plane in modern environments. According to the 2024 Verizon Data Breach Investigations Report, the majority of breaches continue to involve the human element, including stolen credentials and social engineering.

Early warning signs often appear in authentication telemetry before anything else.

Look for:

Repeated failed logins followed by a successful login from the same account
Logins from atypical geographies or impossible travel scenarios
Dormant accounts suddenly becoming active
Privilege escalation requests that do not align with job functions

These are not necessarily breaches. But they are often precursors.

Adversaries frequently test credentials quietly before operationalizing access. The MITRE ATT&CK framework documents techniques such as credential stuffing, password spraying, and valid account abuse under Initial Access and Persistence tactics.

If identity behavior shifts, assume it is meaningful until proven otherwise.

2. MFA Fatigue and Push Bombing

Multifactor authentication is not invincible. Attackers increasingly exploit user behavior instead of cryptographic weaknesses.

Push bombing, also known as MFA (multifactor authentication) fatigue, floods a user with repeated authentication prompts until they approve one out of frustration or confusion. The Cybersecurity and Infrastructure Security Agency has published guidance highlighting this growing tactic.

Early warning indicators include:

Multiple MFA prompts within short time periods
Authentication approvals outside normal working hours
Users reporting repeated push requests they did not initiate

When a user comments, “I keep getting login prompts even though I’m not trying to sign in” that’s not a help desk or internal IT nuisance. It’s an intrusion attempt in progress.

3. Unexpected Changes in Account Permissions

Privilege creep happens naturally over time. Attack driven privilege escalation looks different.

Take notice when you see:

Service accounts added to privileged groups without change control documentation
Administrative roles assigned temporarily and never revoked
API keys created outside normal deployment pipelines

The 2023 IBM Cost of a Data Breach Report noted that organizations with mature identify and access management practices experienced significantly lower breach costs compared to those without.

Access to expansion without operational justification is rarely accidental. It is often reconnaissance or staging.

4. Anomalous Network Behavior that is Subtle

Before large scale data exfiltration occurs, the threat actors have already mapped out the environment. They enumerate systems, prob for open ports, and test lateral movements before escalations.

Signals to look for:

Internal port scanning from a user workstation
Lateral traffic patterns that do not match baseline behaviors
DNS queries to newly registered or suspicious domains

According to the 2024 CrowdStrike Global Threat Report, adversaries continue to reduce breakout times, meaning the time between initial access and lateral movement can be quite short.

If your only alerts are on large data transfers, you may be waiting to react until it’s already at the end of the story. Early detection means paying attention to reconnaissance.

5. Endpoint Drift and Security Control Tampering

Attackers frequently attempt to disable security tooling before executing payloads.

Warning signals include:

Endpoint detection agents being stopped or uninstalled
Logging services disabled or modified
Registry or system configuration changes affecting security posture

Again, the MITRE ATT&CK technique Impair Defenses specifically outlines how adversaries disable or modify security tools to evade detection.

If telemetry goes dark unexpectedly, treat that as an alert, not as an inconvenience.

6. Dark Web Mentions of Corporate Assets

Not all early signals originate inside your environment.

Compromised credentials, exposed API keys, and proprietary data often appear on underground forums and marketplaces before being weaponized at scale. Proactive darknet monitoring can identify leaked corporate emails, password dumps, and access listings tied to your organization.

Routinely monitoring for credential exposure and enforcing password resets and token revocation when compromise is suspected.

External signals can provide a critical time advantage.

7. User Behavior that Feels Off

Security telemetry is critical. So is human intuition.

Sometimes employees notice:

Suspicious emails that somehow bypassed filters
Files appearing in a shared drive that no one claims ownership of
Systems behaving slower or differently than usual

Encouraging reporting without penalty. The 2024 Verizon DBIR emphasizes that human reporting remains a key detection source for many incidents.

If your culture discourages raising small concerns, you will only hear about problems when it is too late.

Why Weak Signals Matter

Attackers operate in stages. Initial access. Persistence. Privilege escalation. Lateral movement. Exfiltration. Impact.

Each and every stage generates signals.

Organizations that wait for definitive proof of compromise are often responding during the Impact phase. At that point, containment becomes expensive and public.

Early warning detection shifts the timeline left.

It creates opportunities to:

Reset credentials before privilege escalation
Isolate endpoints before ransomware deployment
Revoke tokens before data exfiltration

The financial implications are significant. IBM reports that organizations that identified and contained breaches under 200 days save substantially compared to those with longer dwell times.

Speed matters. However, speed cannot increase without signal recognition.