From a technical standpoint, Nigerian Email
Cybercrime is rather challenging. Whilst the rest of the world tries to
engineer technical controls to filter incoming unsolicited email, Nigeria is
faced with the rather usual task of controlling massive amounts of outgoing
unsolicited email. Most available technologies today, are not designed to
address outgoing Email such as the ones we see in the case of Nigeria.
Traditionally, spammers reside outside the external Network, although some
might try to harvest internal Network resources to convey or relay their
messages, SPAM traffic is generally seen as incoming traffic of an external
nature. Hence, most technologies combating unsolicited mail, tend to address
it as undesirable incoming mail.
The solution for the Nigerian Outgoing Email 419, is a reverse engineering
of unsolicited email technologies, that filters these email from leaving
itís source address. In the case of Nigeria, the primary source is the
Nigerian unsolicited email leaves the Nigerian ISP in two forms, A) As
regular SMTP Email, B) As HTTP Web Based mail. An effective solution needs
to address both types of unsolicited mail formats to be effective.
The 419 Email Solicitation System is an advanced Network System, that
inspects both outgoing Email and HTTP packets, performs Paul Grahamís Spam
Filter bayesian statistical analysis (See http://www.paulgraham.com/spam.html),
and than makes a decision on denying or granting a particular Outgoing Email
or Http Request.
The Nigerian 419 Email will consist of the following component:
A) Packet Re-assembly
B) Bayesian Statistical Classification Component
C) Decision Component
D) Spam database
E) Non Spam Database
The System should also be integrated with other unsolicited technologies
A) RBL Blocking System (IP Black list database).
B) OPEN RELAY Testing System.
Conceptual Level 0 Diagram From Nigerian 419 System
Packet Re-Assembly Component
The Packet Re-assemble module separates outgoing SMTP and HTPP packets and
combines them into individual whole messages. There will be two types of
messages. Email and HTTP requests. Each type of message will be stored into
separates Database, and then forwarded to the Bayesian Classification
Bayesian Classification Component
The Bayesian Classification model uses the training Data in the 419 and
non-419 database to assign a probability weight to each individual message,
and classifies the message as 419 or none 419. Http://www.stat.rutgers.edu/~madigan/PAPERS/sagtu.pdf)
The Decision Component evaluates the weighted probability of individual HTTP
and SMTP messages, discards those with probabilities of being 419 messages
and forward Non-419 messages. Denied messages will be granted appropriate
feedback, either in the form a browser message, or in the form of an email
Filtering at the Centralized Internet Exchange Model
A consortium of African Internet Service Providers,have been actively
lobbying for centralized Internet Exchange Points (IXP). The IXPís are
centralized InternetService Points, where national ISPís can collectively
source Internet connectivity and distribute it to their customers.
The most efficient level of content filtering can be implemented at these
IXPís, just for the fact of the
centralized model(http://www.afrispa.org/initiatives.htm) . However, IXPís
in Nigeria are still conceptual, the limitations of this model includes;
economic feasibility and general infrastructure limitations such as
consistent electricity and the availability of an integrated fiber optics
network. The author suggests the implementation of IXPís include 419
filtering solutions for HTTP as well as SMTP traffic in regions with high
Cyber crime traffic.
Nevertheless the prime issue with this model is feasibility. ďIn Nigeria,
there are three companies engaged in the production of telecommunication
cables using imported copper and other local resources like poly vinyl
chloride materials for insulation. There is no company that is cuurently
producing fibre optic cables in the country. The copper cable producing
companies are producing only low pair capacity of 50, 100, 200 pairs. There
is need for a plant that will produce high pair capacity cables that will
enhance massive provision of lines to the teaming population.Ē (http://www.nigeriaembassyusa.org/investment.shtml).
Filtering at the ISP, might not be feasible for some years to come.
BENEFITS OF THE 419 SYSTEM
The Anti-419 System such as the one proposed above has many benefits.
A) It will deny SMTP and HTTP 419 Emails from leaving Nigerian ISP.
B) It can be implemented anywhere at the ISPís Internal Network.
C) It can be implemented as a hardware solution
Please note, that a reputable American Company has agreed to design this
product. Questions for the author regarding the product can be mailed to