Malware in combined JS

Hi,

I’ve been working on a site that was infected with malware. The website has been been cleaned and all scans using WordFence, Sucuri, malCure come up clean. But when I activate SG Optimizer (Hosted on SiteGround) I then get a malware warning in a combined js file in the folder: /uploads/siteground-optimizer-assets/ If I disable the plugin and delete the mentioned folder with combined files, the malware scans are clean.

I can’t seem to work out where it is coming from or how to clean. Any ideas?

I’ve replaced wp-admin & wp-includes folders. As well as all the plugins. I’ve checked all the uploads folders. The scan is clean until the Optimizing plugin is activated.

I’ve cleared website and serverside caches too.

Thanks