Anatomy of An Outsider Attack
The goals of outsider attacks are to prevent detection, maintain a presence in the targeted environment for an extended period, identify targeted data, and exfiltrate the data. As such, most outsider attacks follow a common series of steps:
Planning
After a target organization is identified, attack planning begins. Planning includes researching the company’s infrastructure to determine how the malware will be introduced, the communication methods used while the attack is in progress, and how/ where the data will be extracted. In all cases, multiple paths are defined. If social engineering will be used in the attack, research is conducted to identify high value employees and their social media pages. From these, attackers can collect demographic and historical data, personal email addresses, and data about families and friends including birthdays, addresses, and schools attended. Profile intelligence collected from these activities includes likely passwords or lost password answers, people from whom the target would likely open email, whether home machines or networks are easier to compromise, and what the target’s likely access to data would be based on their title, role, or relationships.
Malware Introduction
Malware is often introduced through social engineering attacks such as spear phishing. These attacks are personalized based on the success of the planning stage. Emails with embedded malware or links to compromised websites are common, but may other types of introduction methods may be used, including software and network vulnerability exploits. Social engineering is one of the most successful attack vectors because, even today, most people do not understand the risk of opening suspect emails and files, or clicking on unverified links. Further, most companies do very little to educate their employees about this risk in an effective way.
Command and Control
In sophisticated attacks, the malware needs to communicate with the attackers to send discovered information and receive additional instructions. Examples include malware that has installed itself on one or more machines and infiltrated the corporate directories and network. It will send user, network, and machine information to the attackers and receive new instructions on what identities or machines to infect next, how to identify the targets, and instructions on how to exfiltrate the data.
Malware Expansion or Lateral Movement
Attackers assume the data they want will reside on multiple machines. Therefore, the malware will need to move laterally to find and access the target data, move the target data to an exfiltration point, and then exfiltrate the data off the network.
Target identification
For our purposes, this step includes the malware finding the machine where the target data is located and gaining access to that data.
Attack Event (Exfiltration)
For a data-focused attack, this step usually consists of two parts. First, it will copy, obfuscate, and move the target data to an exfiltration point. The malware may store the stolen data in temporary passwordprotected RAR, ZIP, or CAB compressed folders. Next, the malware exploits defensive weaknesses to move data off the network.
Weaknesses include remote access applications or FTP sites, email through a malicious SMTP server directly on the compromised system, and DNS (domain name server) extraction. Regardless of what event is used, the Attack Event stage in an outsider attack can take weeks or months, with the malware making multiple attempts to move and extract data, all while remaining hidden to infrastructurefocused security systems.
Retreat or Removal
After a data compromise is complete, the malware will often retreat and hide within a computer network or destroy itself, depending on the target organization and likelihood of discovery by security systems. In high value organizations, the attackers prefer to leave malware in the environment to open new back doors or be used in later exploits.