Adversaries may manipulate products or product delivery mechanisms prior to receipt by a final consumer for the purpose of data or system compromise.
Supply chain compromise can take place at any stage of the supply chain including:
While supply chain compromise can impact any component of hardware or software, attackers looking to gain execution have often focused on malicious additions to legitimate software in software distribution or update channels.    Targeting may be specific to a desired victim set  or malicious software may be distributed to a broad set of consumers but only move on to additional tactics on specific victims.   Popular open source projects that are used as dependencies in many applications may also be targeted as a means to add malicious code to users of the dependency. 
A patch management process should be implemented to check unused dependencies, unmaintained and/or previously vulnerable dependencies, unnecessary features, components, files, and documentation.
Continuous monitoring of vulnerability sources and the use of automatic and manual code review tools should also be implemented as well.
Use verification of distributed binaries through hash checking or other integrity checking mechanisms. Scan downloads for malicious signatures and attempt to test software and updates prior to deployment while taking note of potential suspicious activity. Perform physical inspection of hardware to look for potential tampering.