Font change on Identity Safe log in

I've been using NIS / Identity safe for many years.  Today I went to log into a web site I use regularly and on this occasion my username (which is an alphnumeric Engilsh text) was shown in what I initally thought was chineese.  I did not log in. I copied the charaters into word and it told me they were SimSun-ExtB. I've tried to replicate the name in word, but if I type my user name and try to convert it, my text remains in readable characters.  I did a full system scan the prevoius night before shutting my computer down and only found two low risk tracking cookies.

 

My inital panic that I had picked something up is now receeding, and I've logged into the web site since (and others) with no issues.  However, this is the first time that I've ever had an issue with NIS / IS so I'm wondering if anyone else has experienced this, or if it is a known issue or if it is something to worry about?