I have a Windows Server 2008 R2 system that's showing thousands of 4625 Logon Failure errors with Logon Type 8 (NetworkCleartext) in the Security section of the Windows Logs every single day. There are no IP addresses of the systems trying to gain access listed in the Source Network Address, so the script I built to block IPs that fail too often can't find them.
What services could these login attempts be coming from?
Here is a sample of one of them:
An account failed to log on. Subject: Security ID: SYSTEM Account Name: server-name$ Account Domain: example Logon ID: 0x3e7 Logon Type: 8 Account For Which Logon Failed: Security ID: NULL SID Account Name: Administrator Account Domain: Failure Information: Failure Reason: Unknown user name or bad password. Status: 0xc000006d Sub Status: 0xc0000064 Process Information: Caller Process ID: 0x4d0 Caller Process Name: C:\Windows\System32\svchost.exe Network Information: Workstation Name: system-name Source Network Address: - Source Port: - Detailed Authentication Information: Logon Process: Advapi Authentication Package: MICROSOFT_AUTHENTICATION_PACKAGE_V1_0 Transited Services: - Package Name (NTLM only): - Key Length: 0 This event is generated when a logon request fails. It is generated on the computer where access was attempted. The Subject fields indicate the account on the local system which requested the logon. This is most commonly a service such as the Server service, or a local process such as Winlogon.exe or Services.exe. The Logon Type field indicates the kind of logon that was requested. The most common types are 2 (interactive) and 3 (network). The Process Information fields indicate which account and process on the system requested the logon. The Network Information fields indicate where a remote logon request originated. Workstation name is not always available and may be left blank in some cases. The authentication information fields provide detailed information about this specific logon request. - Transited services indicate which intermediate services have participated in this logon request. - Package name indicates which sub-protocol was used among the NTLM protocols. - Key length indicates the length of the generated session key. This will be 0 if no session key was requested.