Seeds are likely a “brushing scam”
The Federal Trade Commission (FTC) says the mystery seeds appear to be part of a global “brushing scam,” which happens when your name and mailbox are used as props in a fake purchase.
In a brushing scam, a shady company will pay itself for an online order, send an unsolicited package to you as cover and post a fake positive review online in your name — all to get a boost in search results for online stores like Amazon (better reviews = higher search rankings and potentially more business). If Amazon tries to verify the review, the scammer then uses the mail tracking number from the fake order to “prove” that a purchase and delivery were made.
Brushing scams can involve more than just seeds. In fact, the Better Business Bureau (BBB) reports people have received a number of other items in unmarked packages lately, ranging from ping pong balls to masks. However, the mystery seeds seem to be popping up the most.
What to do if you receive mystery seeds:
If you receive strange seeds in the mail, do NOT open them, do NOT throw them away and do NOT plant them. Instead, follow the USDA's advice and forward the package to its closest office: