Stock spammers currently promoting PRTH.PK are continuing to try new variants in the hope of getting through. Some recent spams have included attachments in '.fdf' format (used for fillable PDF forms) and there have also been extensive plaintext floods, using various degrees of obfuscation to try to get around spam filters. Yesterday's flood, which delivered 338 messages to our spam traps, was the largest single-day stock spam run we've seen to date.