The first thing to do is make sure your code can't allow it again! But assuming that you have done that...
If you mean you need to find all the rows and columns containing that specific text, you can use the CONTAINS clause in your WHERE,
provided your table is full text indexed.:
SELECT * FROM MyTable WHERE CONTAINS((Column1, Column2), '<title><style fontsize:10px>')
If it isn't, then you will have to use a LIKE clause on each column specifically.