Getting lots of Audit Failures in Event Viewer > Security on Windows Server 2008 R2

Over the past few days we have been getting loads of audit failures on the event viewer > security. I suspect they hackers trying to gain access to the server, but they fall into 2 types:

One where an IP address is being captured

    An account failed to log on.

Subject:
    Security ID:        NULL SID
    Account Name:       -
    Account Domain:     -
    Logon ID:       0x0

Logon Type:         3

Account For Which Logon Failed:
    Security ID:        NULL SID
    Account Name:       Administrateur
    Account Domain:     FXNB

Failure Information:
    Failure Reason:     Unknown user name or bad password.
    Status:         0xc000006d
    Sub Status:     0xc0000064

Process Information:
    Caller Process ID:  0x0
    Caller Process Name:    -

Network Information:
    Workstation Name:   FXNB
    Source Network Address: 119.245.156.11
    Source Port:        40924

Detailed Authentication Information:
    Logon Process:      NtLmSsp 
    Authentication Package: NTLM
    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.

In which case I'm adding these IP addresses to a blocking rule on the firewall.

The second type is like this:

An account failed to log on.

Subject:
    Security ID:        SYSTEM
    Account Name:       DEDICAT-93I3U5A$
    Account Domain:     WORKGROUP
    Logon ID:       0x3e7

Logon Type:         8

Account For Which Logon Failed:
    Security ID:        NULL SID
    Account Name:       test@casamiadumfries.com
    Account Domain:     

Failure Information:
    Failure Reason:     Unknown user name or bad password.
    Status:         0xc000006d
    Sub Status:     0xc0000064

Process Information:
    Caller Process ID:  0x630
    Caller Process Name:    C:\Windows\System32\svchost.exe

Network Information:
    Workstation Name:   DEDICAT-93I3U5A
    Source Network Address: -
    Source Port:        -

Detailed Authentication Information:
    Logon Process:      Advapi  
    Authentication Package: Negotiate
    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.

Where there is no IP address captured. It always seems to be Caller Process ID: 0x630, but when I look under task manager there is never a PID of 630 under processes or services, even showing processes from all users.

Both types of fail use user names which are either misspelling of administrator, generic user names, like test123, guest, fred etc, or variations on websites we host, as in the second example, test@casamiadumfries.com.

I'm ok dealing with the first type of fail, but I've got no idea how to approach the second type of fail or what it implies.

Would really appreciate any help at all. Thanks in advance.