Comment by eridius

How is it a backdoor? System services don't typically source the user's bash profile before running, and even if they did, they don't run from attacker-controlled directories anyway. At best you could compromise someone by tricking them into cd'ing into a folder you provided, but that's not something that would generally be called a "backdoor". And if you can get them to run your install script, you've already "compromised" them anyway and LD_LIBRARY_PATH is completely unnecessary.