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LearnDefend
Authentication & Identity
TheoryBeginner11 minWindows SecurityLog Analysis

Logons: 4624, 4625 & Logon Types

What is it?

4624 is a successful logon, 4625 a failed one. The LogonType field says HOW: 2 interactive (at the keyboard), 3 network (SMB/shares), 10 RemoteInteractive (RDP). The type reframes what a logon means.

Why it matters

A failed-then-successful 4625→4624 burst from one source is brute force; a Type-10 RDP logon from an unusual host is a lateral-movement lead. The type and outcome carry the meaning.

Where you see it

4625 rows with LogonType 3 and a Source IP; a 4624 with LogonType 10 names the RDP session; the Account and Computer fields tell you who and where.

What normal looks like

Interactive (2) logons at desks during hours; a few stray 4625 typos; service logons on their schedule.

What suspicious looks like

Many 4625 then a 4624 from one external source (brute force), or an off-hours Type-10 RDP from a workstation that never does RDP.

How analysts investigate

Group 4625 by source and account to spot a burst, read the LogonType to understand the vector, and check whether a success followed the failures from the same source.

Common beginner mistakes

  • Ignoring LogonType — a network vs interactive logon means very different things.
  • Treating a lone 4625 as an attack instead of a typo.

Success, failure, and how

  4625  02:11  a.hakim  src 203.0.113.66  LogonType 3   (fail)
  4625  02:11  a.hakim  src 203.0.113.66  LogonType 3   (fail x4)
  4624  02:11  a.hakim  src 203.0.113.66  LogonType 3   (SUCCESS)
  → failures then success from ONE external src = brute force in
  LogonType: 2 interactive · 3 network · 10 RDP
4625/4624 plus the LogonType and source reveal the vector and whether an attack succeeded.

Quick check

Five 4625s then a 4624, all from one external IP for one account. What is it?

A quick self-check — it doesn't affect your XP or progress.

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