AD brute force attack

Özgür Gül 1 Reputation point

Hi guys,

Today when i was inspecting security event logs at active directory server i realised we are recieving constant password brute force attacks from different user accounts.

Usernames were seeming to be coming from a rainbow table as; Jessie, Jaxon, on

Source workstation is also seeming to be different on each try as; Windows7, Remmina, Windows2019, Windows10, FreeRDP... (these hosts does not seem to appear on network when i do nslookup control)

The question is i have no identifier to reach an ip address to reach the attacker device.

I am adding an example log output and info i got, and i need guidance to reach further information on which device is sending this requests.

Logon Account: Matthew
Source Workstation: FreeRDP
Error Code: 0xC0000064

Active Directory
Active Directory
A set of directory-based technologies included in Windows Server.
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Windows Server Security
Windows Server Security
Windows Server: A family of Microsoft server operating systems that support enterprise-level management, data storage, applications, and communications.Security: The precautions taken to guard against crime, attack, sabotage, espionage, or another threat.
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  1. Mohammed Altamash Khan 2,081 Reputation points

    step 1 is to block this IP on you network device like firewall , or something .
    Unblock it only when you verify who was the owner of device and IP source is trusted.