Correlations and Omori law in Spamming

TL;DR

This paper analyzes the temporal patterns of spam emails, revealing correlations and applying the Omori law to model spam delivery times, which could help understand and predict spam behavior.

Contribution

It introduces a novel statistical analysis of spam intertimes showing correlations and models them using the Omori law, providing insights into spammer operation strategies.

Findings

Spam intertimes are statistically correlated.

Spam delivery follows the Omori law pattern.

A numerical model reproduces observed spam timing correlations.

Abstract

The most costly and annoying characteristic of the e-mail communication system is the large number of unsolicited commercial e-mails, known as spams, that are continuously received. Via the investigation of the statistical properties of the spam delivering intertimes, we show that spams delivered to a given recipient are time correlated: if the intertime between two consecutive spams is small (large), then the next spam will most probably arrive after a small (large) intertime. Spam temporal correlations are reproduced by a numerical model based on the random superposition of spam sequences, each one described by the Omori law. This and other experimental findings suggest that statistical approaches may be used to infer how spammers operate.