I have dealt with Hakin9 a few years ago and was extremely disappointed by how they handle themselves. After publishing my article (a piece about overwriting system calls by rewriting pointers in the system_table and practical uses) it took them close to 10 months to be paid and only did so after harassing them for months.

Its hilarious, albeit not too surprising, that they published this without even bothering to read it (they crowdsource their proof reading and expect beta readers to report if they are about to publish something inaccurate or outright stupid).