Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: An In-depth Analysis of Spam and Spammers   Electronic mail services have become an important source of communication for
millions of people all over the world. Due to this tremendous growth, there has
been a significant increase in spam traffic. Spam messes up user's inbox,
consumes network resources and spread worms and viruses. In this paper we study
the characteristics of spam and the technology used by spammers. In order to
counter anti spam technology, spammers change their mode of operation,
therefore continues evaluation of the characteristics of spam and spammers
technology has become mandatory. These evaluations help us to enhance the
existing anti spam technology and thereby help us to combat spam effectively.
In order to characterize spam, we collected four hundred thousand spam mails
from a corporate mail server for a period of 14 months from January 2006 to
February 2007. For analysis we classified spam based on attachment and
contents. We observed that spammers use software tools to send spam with
attachment. The main features of this software are hiding sender's identity,
randomly selecting text messages, identifying open relay machines, mass mailing
capability and defining spamming duration. Spammers do not use spam software to
send spam without attachment. From our study we observed that, four years old
heavy users email accounts attract more spam than four years old light users
mail accounts. Relatively new email accounts which are 14 months old do not
receive spam. But in some special cases like DDoS attacks, we found that new
email accounts receive spam and 14 months old heavy users email accounts have
attracted more spam than 14 months old light users. We believe that this
analysis could be useful to develop more efficient anti spam techniques.

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The categories of this paper are: atom-ph
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
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The categories of this paper are: mtrl-th
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The categories of this paper are: alg-geom
9
The categories of this paper are: nlin
33
The categories of this paper are: plasm-ph
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
18
The categories of this paper are: econ
14
The categories of this paper are: math-ph