File modified by attachFile?

[rswerve]

I'm writing a test that uploads a known virus (the benign Eicar virus file: https://www.eicar.org/download-anti-malware-testfile/) in order to test our virus-scanning service. The issue is that after calling attachFile, my uploader is receiving a file that's slightly different from the original file--different sha, no virus. Uploading the file manually works as intended: it is rejected for containing a virus. The project is open source, so you can see the test here: https://github.com/CMSgov/managed-care-review/blob/ma_3029_upload_virus/tests/cypress/integration/stateWorkflow/virusScan/virusScan.spec.ts#L16

Is there any reason to suspect that attachFile would modify a file containing a virus?

[rswerve]

To answer my own question, attachFile is a method from the cypress-file-upload package, and the encoding of the file had to be set manually to 'binary' in order for the file not to be mangled.