DoS and Windows Login

["Nicholas C. Weaver" <nweaver () CS Berkeley EDU>]

UC Berkeley runs a fairly open network (*GASP*, no firewall).

Lately, many users have been experiencing a minor but annoying DOS
attack: The windows system's authentication procedures, after X failed
password tries, locks out the account for 30 minutes.  Someone or some
group is doing large scale password guessing which is resulting in
many users being unable to log in in the morning, until this timeout
passes.

Question:  Have those in other universities or other generally open
computing environments noticed a similar trend?  Is this the work of
an attacker trying to brute-force passwords or a deliberate DOS
attempt?

-- 
Nicholas C. Weaver                                 nweaver () cs berkeley edu

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