Due to the ever increasing inter-dependency across a variety of diverse software and hardware components in ICT provisioning, supply chain vulnerabilities (SCVs) targeting such dependencies have evolved as a primary choice for malicious actors to initiate stealthy and complex cyber-attacks. The current modus operandi within the modern cyber threat spectrum is solely correlated with APTs that have shown to be quite prevalent across diversified attacks underpinning cyberwarfare, cyber terrorism and cybercrime in general. Thus, defense against such events is undoubtedly considered as a high priority on a global scale. Nonetheless, the integration of and dependence on third-party supply chain software and devices located at heterogeneous ICT ecosystems in parallel with the inability of current defense mechanisms to pinpoint nor consider enable a plethora of compromise entry points that consequently amplify APTs. Motivated by these challenges, this survey explores the state-of-the-art to (i) stratify and showcase the properties of supply chain-based APTs, (ii) elaborate on reported risks from such APTs, and, (iii) expand on existing defense methods as proposed until recently. The herein reported study aims to also relate academic research with industry practices having as a greater goal to expose this emerging issue and equip cybersecurity practitioners with the required knowledge for designing next generation APT defense mechanisms.