Learn Email Investigation Techniques and Procedures

author
Published By Jamie Kaler
Rollins Duke
Approved By Rollins Duke
Published On November 28th, 2023
Reading Time 4 Minutes Reading
Category Tips and Tricks

The email has become one of the most used communication applications. It is used to exchange data and perform data transactions. Due to the increased use of emails in the current scenario, your security has also become a major problem. Nowadays, emails act as the main weapon to commit a crime. Email phishing, fraud, sexual predation, the sending of unwanted emails, the injection of viruses through emails and more among the main crimes committed by the perpetrators with the help of emails. In addition, different types of data theft through emails can negatively affect functioning.

Whenever a digital or cybercrime arises, the first step is to consult the data researchers. Digital investigators collect, preserve and analyze emails to investigate a crime. For an efficient and in-depth investigation of emails, a wide variety of tools and procedures are used. In the next section, we will shed some light on the procedures and various techniques used for an efficient investigation of emails in a particular crime.

Procedure to Investigate an Email

In forensic analysis, the source and content of emails considered the evidence. The process includes the identification of the actual sender, the recipient, the date, time and location of the mail transaction, the intention of the sender, etc. It also involves researching metadata, searching for keywords, analyzing ports, etc.

  1. Header Analysis OF Emails
    While researching emails, we usually start from scratch and analyze the headers of the emails. The headers contain information about the senders of the emails. Also, information about the route through which the emails have traveled. During the time of a crime, the headings of the emails forged to hide the identity of the sender. If the messages that pass through the SMTP server do not have the synchronization of SMTP ideas, then they are false.
  2. Link Analysis
    Link analysis is a method of analyzing graphical data to evaluate the emails exchanged between users. Since the crime may involve multiple suspects, the link analysis examines the link between the suspects. Thousands of emails linked between the suspects, therefore, it becomes a time-consuming task and voids the purpose of email research.
  3. Bait Tactics
    The basic aim of the bait tactics is to extract the IP address of the culprit. In this technique, an email with http:<img src>tag which has some image source at a computer that is monitored by investigators is sent to the email address that under investigation. Now the recipient is the one who originally was sender during the crime. When the email opens, a registry entry containing the recipient’s IP address registered on the server. It is an accommodation of the image and the recipient tracked. In the event that the recipient is using a proxy server, the researchers will record the IP address of the proxy server.

Some more methods to Investigate Emails

  1. Investigation Of Server
    In server research, server logs and copies of messages delivered between sender and receiver investigated. Sender and recipient emails that can’t get recovered, received or extracted from proxy servers or ISP. Since servers store a copy of all emails after their respective delivery. In addition, the SMTP server that stores the details.  Such as the credit card number and other data associated with a particular user, used to identify the owner of the particular email address.
  2. Investigating Network Device
    The source of an email message investigated with the help of logs maintained by network devices such as routers, firewalls, and switches. Owing to its complexity, this technique deployed in the absence of logs of ISP or proxy servers only. Unavailability of server logs may occur due to various reasons like the absence of a chain of evidence.
  3. Fingerprints Of Sender Mailers
    The received header field proves to be helpful in the identification of software which handles email at the server. Also, a different set of headers like “X-Mailers” used for the identification of the software which handles email at the client. These headers describe information about the applications and their servers used by the client to send emails.
  4. Software Embedded Identifiers
    The information about the creator of emails included in the custom headers or in the form of MIME contents as a TNEF. The investigation may reveal names of PST files, MAC address, etc. of the computer, which was used to send emails.

Conclusion

Using the correct technique to investigate emails in cybercrime is an essential aspect to discover the culprit. Therefore, an efficient technique in a timely manner helps to prove that a culprit is at fault in the lawsuit.