Occupational Fraud Detection Through Visualization

Occupational fraud affects many companies worldwide causing them economic loss and liability issues towards their customers and other involved entities. Detecting internal fraud in a company requires significant effort and, unfortunately cannot be entirely prevented. The internal auditors have to process a huge amount of data produced by diverse systems, which are in most cases in textual form, with little automated support. In this paper, we exploit the advantages of information visualization and present a system that aims to detect occupational fraud in systems which involve a pair of entities (e.g., an employee and a client) and periodic activity. The main visualization is based on a spiral system on which the events are drawn appropriately according to their time-stamp. Suspicious events are considered those which appear along the same radius or on close radii of the spiral. Before producing the visualization, the system ranks both involved entities according to the specifications of the internal auditor and generates a video file of the activity such that events with strong evidence of fraud appear first in the video. The system is also equipped with several different visualizations and mechanisms in order to meet the requirements of an internal fraud detection system

The phenomenon of spam and the use of "honeypot" traps to study it

86 σ.Το θέμα της εργασίας είναι η μελέτη του φαινομένου της ανεπιθύμητης ηλεκτρονικής αλληλογραφίας. Αρχικά, αναφέρονται τα βασικά χαρακτηριστικά των μυνημάτων αυτών, που αναφέρονται ως spam, οι διάφορες κατηγορίες περιεχομένου και οι βασικότερες συνέπειες αυτού του φαινομένου. Στο Κεφάλαιο 2, περιγράφεται η διαδικασία παράδοσης των e-mails και εξετάζεται ο τρόπος με τον οποίο αυτή μπορεί να αναπαρασταθεί ως κατευθυνόμενος γράφος. Το Κεφάλαιο κλείνει με την ανάλυση των πιθανών διαδρομών που μπορούν να ακολουθήσουν τα spam από τον αποστολέα τους σε κάποιο παραλήπτη. Στο Κεφάλαιο 3, αναφέρονται τα κυριότερα anti-spam μέτρα, τα οποία χωρίζονται σε νομικά, οργανωτικά, συμπεριφορικά και τεχνολογικά. Στο τελευταίο Κεφάλαιο, αναφέρεται ο τρόπος με τον οποίο μπορούν να χρησιμοποιηθούν παγίδες “honeypot” για τη μελέτη του φαινομένου του spam, καθώς και μία υλοποίηση τους για τη μελέτη της παράμονης συλλογής διευθύνσεων e-mail από ιστοσελίδες.The theme of this diploma thesis is the study of the phenomenon of spam. Initially, we indicate the main characteristics of these e-mails, referred as spam, the various content categories and the main consequences of this phenomenon. In Chapter 2, we describe the procedure of e-mail delivery and we examine the way in which this can be represented as a directed graph. The chapter concludes with an analysis of possible routes that can be followed by spam. In Chapter 3, we indicate the main anti-spam measures, which are divided into legal, organizational, behavioral and technological measures. In the last chapter, we describe how "honeypot" traps can be used in order to study the phenomenon of spam, and an implementation of this methology is included in order to study the phenomenon of e-mail addresses harvesting from websites.Αικατερίνη Α. Σωτηράκ