Massive Spike in Direct Traffic for 1 Day

[KiffTay]

In GA I have 2 views for the same property; one where only traffic with our domain name is in the hostname is shown (to exclude ghost spam) and the other with no filters applied. I usually use the latter, but the stats are relatively similar.

Today I logged into the ghost spam view and there was a massive spike in direct traffic on Wed 16th March - I'm talking at least 4,000 more than we usually get. Now because of the filter that's applied, and because it's direct, I don't know what could be behind the cause of the spike. Levels are now back to normal for the time being.

Does anyone have any idea what could be behind the spike - and will it have any adverse effects?

Many thanks in advance for any replies!

[Andy Langton]

only traffic with our domain name is in the hostname is shown

So, it was traffic that came through with either blank or alternative hostname. Check the hostnames that were actually sent via the Network report in GA. It's very likely to be spam. Otherwise, it's possible someone else installed your code on their page. The hostnames will give you at least some idea, however.