If that's all that's written on the CPU than it looks like it might be an engineering sample. That writing isn't the normal format. Usually it'll go something like:
(Above the die)
Intel®© '01 Malay
933/256/133/1.75
(Below the die)
Q143Axxxx-xxx
Pentium III SL5xx
The sSpec code is the "SL5xx" number at the bottom. If your CPU has that you can look it up using the link provided above and find out all the particulars about your CPU. If the writing's not in that format you may have an engineering sample.
Edit: after doing a little more checking I found that the number "RB80526PZ933256" is the Intel retail box stock number for a 933mhz socket 370 PIII. So maybe it is legit. If it's a regular 933 Coppermine it should be 1.75V.