I recently came across an article on the The Verge, which centers around the concept of commercial malware production and how it's used around the world. The article introduced me to a number of interesting (and worrisome) concepts such as "process hollowing", remote access to hardware that's hidden from the system/user etc..
While I have no reason to have similar worries mentioned in the article, working with IT issues and developing in Java, together with the recent major bugs (shellshock, heartbleed etc) and the ever increasing complexity of the malware makes me quite paranoid about the vulnerabilities of the systems I use and administer.
Whenever I notice a suspicious behaviour (such as unusual slowness, random wake from sleep, high cpu load while not actively running demanding software) I tend to check the running processes on my mac/*nix machines. I have so far not come across anything that caught my eye, but that doesn't mean there are no "hollow" processes.
Is there a way to investigate the an OSX or Linux system, to check whether or not there's hidden malware?