Many applications write various information into log files and sometimes this information is sensitive, e.g. contains user passwords. In my case, I knew that we are logging SQL statements with stored procedures calls and one of the parameters may contain user’s password. So I have been asked to replace such passwords with something neutral.
I’ve ended with following regular expression string (works only for stored procedures and alike call logs!):
(?<Pre>(pass(word)?|pwd)[^=']*=[^']*'?)(?<Target>[^']+)(?<Post>'?)