Chapter 6: VoIP Interception and Modification

email one
Attention: Human Resources
Joe Smith, my assistant programmer, can always be found
hard at work in his cubicle . Joe works independently, without
wasting company time talking to colleagues. Joe never
thinks twice about assisting fellow employees , and he always
finishes given assignments on time. Often Joe takes extended
measures to complete his work, sometimes skipping
coffee breaks. Joe is an individual who has absolutely no
vanity in spite of his high accomplishments and profound
knowledge in his field. I firmly believe that Joe can be
classed as a high-caliber employee, the type which cannot be
dispensed with. Consequently, I duly recommend that Joe be
promoted to executive management, and a proposal will be
executed as soon as possible.
Regards,
Project Leader

email two
Attention: Human Resources
Joe Smith was reading over my shoulder while I wrote the report sent to you earlier today. Kindly read only the odd numbered lines [1, 3, 5, etc.] for my true assessment of his ability.
Regards,
Project Leader
Anonymous HR emails

Overview

With VoIP, any omission or alteration of the media streams may drastically change the meaning of a conversation. It's beyond the scope of this book to delve into a study of linguistics ; however, as you can see from the above emails, substituting, removing, or replaying spoken words in a conversation can obviously have drastic consequences in a variety of social contexts. If a mischievous attacker is situated between two talking parties and is able to intercept and modify the traffic, there are a variety of malicious things he can do.