Outlook bombards Safari users with endless downloads • The Register

Update Attention Mac users accessing Outlook with Safari: something is wrong, and it’s causing an empty TokenFactoryIFrame to download every few seconds as long as you stay there.

Microsoft hasn’t said what’s causing the problem, though it did acknowledge the ongoing error in it. support message board thread on Microsoft Answers. We understand that this flood of downloads affects Safari on desktop Macs; it may also affect browsers on iOS using Safari’s WebKit engine, such as Microsoft Edge on iPad.

The Redmond giant noted in an article dated May 3: “We have recently received several reports that customers are experiencing the issue when visiting Outlook in a Safari browser on Mac, it keeps downloading the iframe from the token factory. We are researching on our end to see if we can find any relevant information about the issue.” Microsoft did not respond to questions from The register.

It seems the problem started on May 2, with several users posting to Microsoft’s help forums complaining about the problem. It also seems widespread: this support board wire on downloads has been viewed over 100,000 times, received hundreds of replies, and suggests that to this day the bug is still present. Users of Apple’s help forums have also reported the problem.

Günter Born, engineer and community moderator for Microsoft Answers in Germany, compiled the complaints from Internet users in a blog post, where he stated that it appears the issue is Microsoft-related. “I linked this article in my Microsoft Answers forum post and asked the forum moderators to escalate the issue to the responsible Microsoft product group – that’s all I can do,” Born said.

According to feedback collected by Born, the bug only seems to occur when Safari users point their browser to Office 365’s Outlook Web Access. A user who investigated the issue said they noticed in the Safari Developer Console a “Failed to load resource” error with a code of 400 (bad request) pointing to a TokenFactoryIFrame. Several reports indicate that the bug occurs in the most recent version of Safari (15.4) and several versions of macOS.

Several websites have created reports to offer a solution to the “TokenFactoryIFrame Mac virus”, but there is no indication that the file contains malware. Several posters in the Microsoft Answers thread indicated that the file was zero bytes long.

Until Microsoft determines the cause of the problem and rolls out a fix when complete, it is possible to adopt a workaround by setting the Outlook365 download preferences in Safari to decline, but note that this will prevent all downloads from Outlook until it is restored.

You can also use another browser to access Outlook Web Access, or use the Outlook app or Mail app provided for macOS. ®

Updated to add

It seems the bug was a server-side error in Microsoft’s domain. The company reported in the bug thread that the issue has been resolved and they have confirmed to customers that OWA is back to working order.

Sam D. Gomez