Please note that any information provided in this thread may not be approved or supported by Imperva.
Please check with Imperva support for an approved solution.The pdf reports do not use a simple graphics file to include the image on the cover page.
There are pdf template files used to create the various cover pages.
These can be found in
/opt/SecureSphere/server/SecureSphere/jakarta-tomcat-secsph/webapps/SecureSphere/reportres/pdftmpl on your MX.
I copied
template_cover_page.pdf down from the MX.
I do not have a pdf editor, so I opened it with word, changed the graphic then printed it as a pdf document.
I made a backup of the original, and uploaded the new file.
I created a pdf report, but the cover page was missing the new logo.
I copied the original template back, ran the report, and it has the Imperva logo.
So you could try editing the template. I did not restart the MX software, not sure it would change anything.