5 Signs You’re Already Under Attack and Don’t Know It Yet

Cyberattacks don’t always kick down the front door. Sometimes, they just walk in… quietly.

The nastiest threats? They’re the ones that whisper. Credential stuffing, internal reconnaissance, lateral movement: they sneak past your perimeter, make themselves comfortable, and wait.

Here are five often-overlooked red flags that might mean you’re already under siege, you just haven’t noticed yet.

1. Unexplained Performance Degradation

What You See:

• Pages dragging like it’s 1998.
• Servers bogged down during off-hours.
• Users complaining about sluggish logins or checkout delays.

What It Might Be:

• Credential-stuffing bots hammering login forms.
• DDoS dress rehearsals to probe your defenses.
• Malware quietly siphoning CPU, memory, or bandwidth.

Check This:
Peep your server CPU, memory, and I/O usage. Use tools like top, htop, or your favorite dashboard. If the metrics spike but user traffic doesn’t, something’s up.

2. A Surge in Failed Login Attempts

What You See:

• Login fails exploding across user accounts.
• Reset requests popping up — but nobody asked for them.
• Logins from odd geolocations or unknown devices.

What It Might Be:

• Credential stuffing with leaked passwords.
• Brute-force guessing games.
• Low-key account takeover attempts.

Check This:
Check your authentication logs. If multiple users are getting hammered at once, it’s not random — it’s reconnaissance.

3. Anomalies in Application or Access Logs

What You See:

• Requests for URLs like /wp-login.php (on a site that ain’t WordPress).
• A sea of 404s, especially for files like .env, config.php, or admin.php.
• Weird HTTP methods (PUT? OPTIONS?) where only GET/POST should live.

What It Might Be:

• Scanners like Nikto or Burp Suite mapping your surface.
• Bots probing for entry points.
• Script kiddies (or worse) hunting misconfigured endpoints.

Check This:
WAF or access logs are your friend. Look for bursts of strange patterns, not just single anomalies.

4. New or Modified Privileged Accounts

What You See:

• Surprise admin accounts showing up.
• Regular users getting unexpected power-ups.
• Account changes nobody remembers approving.

What It Might Be:

• An attacker building a backdoor with admin creds.
• Lateral movement from one compromised account to another.

Check This:
Check IAM audit logs, your DB’s user list, and changes to sudoers or ACLs. If permissions are changing without a paper trail — you’ve got a problem.

5. Outbound Traffic to Weird or Unknown IPs

What You See:

• Your servers talking to IPs they’ve never met.
• POST requests or encrypted packets heading to sketchy domains.
• DNS queries for domains that look like they were named by a cat walking on a keyboard.

What It Might Be:

• Beaconing from malware or RATs (remote access trojans).
• Active data exfiltration.
• A command-and-control (C2) connection waking up.

Check This:
Inspect outbound traffic. netstat, iftop, nethogs, or firewall logs will do the trick. If your infrastructure is calling international strangers at 3 a.m., that’s not “just how the internet works.”

What You Can Do About It

Monitor everything, especially auth activity, application logs, and DNS traffic. But don’t just log it, correlate it. Spikes in system load, failed logins, and weird access patterns aren’t random. Together, they often paint a very clear picture.

Set behavioral baselines and alert on anomalies, not just hard errors. Tools like CrowdStrike, Wazuh, and Splunk UEBA can help you detect when something breaks the pattern.

And when something seems off (even just a handful of 404s or a one-off CPU spike) don’t shrug it off. That might be the breadcrumb that leads you to the breach.

The best time to investigate it? Yesterday. The second-best? Right now.