80 events explained
Your computer wrote something alarming. Here is what it meant.
Event Viewer and log files are written for machines, not for the person reading them at eleven at night. Every entry here says what the line means, whether it is actually bad, and what to do about it.
Aug 28 2026 09:41:17 fw-edge-01 : %ASA-4-106023: Deny tcp src outside:198.51.100.77/49820 dst dmz:192.0.2.15/3389 by access-group "outside_access_in" [0x8ed2f1c1, 0x0]means
Cisco ASA 106023: Traffic denied by an access-list
The firewall dropped a packet because no rule allowed it. This is the firewall doing its job, and on an internet-facing device it fires constantly. It only matters when the traffic was supposed to work, or when the pattern looks like scanning.
Browse by where it came from
Pick the log the line came out of. If you are not sure, Windows System is where crashes and restarts are recorded.
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Windows Security
Sign-ins, account changes, and privilege use, recorded in the Windows Security log.
32 entries -
Windows System
Crashes, restarts, services, and disk errors — what Event Viewer shows when something goes wrong.
18 entries -
Windows Application
Programs crashing, and what the faulting module actually tells you.
1 entry -
PowerShell
Script block logging and what PowerShell records about the code it runs.
1 entry -
Sysmon
Microsoft's free endpoint logging tool, and the events that make it worth deploying.
13 entries -
Linux syslog
SSH, sudo, and PAM messages from /var/log/auth.log and journald.
6 entries -
Linux auditd
Kernel-level audit records, and how to read a multi-line audit event.
2 entries -
Cisco ASA
Firewall syslog messages — denies, permits, and connection records.
5 entries -
iptables & UFW
Linux firewall log lines, and how to read the key-value format.
2 entries