Admin page images distorted

[ABG2009]

Hello,

I'm using 1.3.6 with the latest security patch.

I'm having this strange issue where all of the images in the admin section are badly pixelated. I've set permissions on the images folder to 755.

I was recently hacked, and I'm pretty sure I've recovered. My storefront is having no issues with images looking strange. I've checked every page.

The attached image shows an example.

Thanks in advance!