The most important thing you can do is seek God's will for your future, including His will about this job (or any other opportunities you may have). The Bible says, "In all your ways acknowledge him, and he will make your paths straight" (Proverbs 3:6).
After all, God knows all about you, and He loves you and wants what is best for you. He also knows all about this potential job and whether this report is true or if it's simply the grumbling of a discontented ex-employee. This is why I urge you to pray for God's guidance, asking Him to show you what His will is for your future.
Begin by committing your life to Jesus Christ, if you have never done so; it is the most important decision you will ever make. Then ask Him to give you wisdom about the job offer. Don't accept it just because the pay is good or because it's your only choice right now. God is able to open other doors, if this isn't the right job for you.
Above all, however, don't compromise your integrity or do things that are unethical or dishonest, no matter what job you take or how much pressure you get. At the time it may seem like the best thing to do, but God never rewards dishonesty. The Bible says, "No good thing does he withhold from those whose walk is blameless" (Psalm 84:11).