In what is being described as an “industrywide phishing scheme,” hackers have posted online the names and passwords of tens of thousands of e-mail users. Many users were denied access to their accounts or encountered forced password resets as service providers took defensive precautions Tuesday.

BBC News reported that more than 30,000 names and passwords may have been compromised from AOL, Comcast, Earthlink, Gmail, Yahoo!, Microsoft’s Windows Live Hotmail and other service providers. While some of the accounts appear to be outdated or fake, BBC News confirmed that many are genuine.

Phishing scams involve e-mail messages — often warnings about a fake security breach of a bank account or login name — asking recipients to click on a link to take them to a Web site so they can enter their correct information.

“Phishing is an industrywide problem and Microsoft is committed to helping consumers have a safe, secure and positive online experience,” Microsoft officials wrote in a blog post Monday. “Our guidance to customers is to exercise extreme caution when opening unsolicited attachments and links from both known and unknown sources, and that they install and regularly update their anti-virus software.

“If you believe you’ve been a victim of a phishing scheme, it’s very important that you update your account information and change your password as soon as possible.”

Microsoft said its company servers were not violated in the attack.

The neowin.net technology blog first reported details of an Oct. 1 attack on Hotmail users, noting that account login information was posted to pastebin.com, a popular Web site developers use to share code. Pastebin.com was down for maintenance Tuesday night.

— Noozhawk publisher Bill Macfadyen can be reached at wmacfadyen@noozhawk.com. Follow Noozhawk on Twitter: @noozhawk.

Bill Macfadyen is Noozhawk’s founder and publisher. Contact him at wmacfadyen@noozhawk.com, and follow him on Instagram: @bill.macfadyen. The opinions expressed are his own.