Enlarge / Supply-chain attacks, like the latest PyPI discovery, insert malicious code into seemingly functional software packages used by developers. They’re becoming increasingly common. (credit: Getty Images)

PyPI, a vital repository for open source developers, temporarily halted new project creation and new user registration following an onslaught of package uploads that executed malicious code on any device that installed them. Ten hours later, it lifted the suspension.

Short for the Python Package Index, PyPI is the go-to source for apps and code libraries written in the Python programming language. Fortune 500 corporations and independent developers alike rely on the repository to obtain the latest versions of code needed to make their projects run. At a little after 7 pm PT on Wednesday, the site started displaying a banner message informing visitors that the site was temporarily suspending new project creation and new user registration. The message didn’t explain why or provide an estimate of when the suspension would be lifted.

Screenshot showing temporary suspension notification. (credit: Checkmarx)

About 10 hours later, PyPI restored new project creation and new user registration. Once again, the site provided no reason for the 10-hour halt.