A long-time client of mine sent me an e-mail yesterday asking me if she needed to to this. She received an e-mail, in the body of the e-mail was this message:
"You will not be able to access your Intuit QuickBooks without updated Intuit Security Tool (IST™) after 31th of August, 2012.
You can update Intuit Security Tool here.
After a successful download please run the setup for an automatic installation, then login to Intuit Quickbooks online to check that it is working properly."
As long as you have your QuickBooks set to Auto Update, you have all the security updates that you need. Intuit will never contact you like this asking you to click on a link.
If you're ever unsure of any link sent to you in any e-mail, hover your pointer over the link, in a moment it will display the web address of the link it's taking you to. In this case it was not Intuit.
I'm so glad she asked! You can never be too careful!