The coupon codes themselves are fine - but go to HPs website yourself, not the link they send you to. Its too easy to make a website clone that looks like www.hp.com.a0987rdfaf.net, and grab all entered data.
Is it safe to use random discount codes?
A coupon code is always free – If you ever come across a website that asks for some cash to give you a 50 percent coupon code, get away from that. Its a scam. A legitimate site that cares about their customers and offers coupon codes will never try to sell them.
Can coupon codes be hacked?
A hacker can brute force the coupon code field value by trying all combinations of alphanumeric values of a certain length (usually 4 to 10 characters). Easier said than done, this technique is possible but strongly depends on the hackers available processing power.
Yes, it is legal to apply a promo code to your purchase and avail a discount. But only if you apply a promo code that has been taken from a legitimate website. Promo codes that are given by a brand or an enterprise can be found on their online partners and can be availed for FREE.