A Cyber Journey

 

Reconnaissance is discovering and collecting information on the system and the victim. The reconnaissance phase is the planning phase for the adversaries.

OSINT (Open-Source Intelligence) also falls under reconnaissance. OSINT is the first step an attacker needs to complete to carry out the further phases of an attack. The attacker needs to study the victim by collecting every available piece of information on the company and its employees, such as the company’s size, email addresses, phone numbers from publicly available resources to determine the best target for the attack.

Weaponisation

After a successful reconnaissance stage, “Megatron” would work on crafting a “weapon of destruction”. He would prefer not to interact with the victim directly and, instead, he will create a “weaponizer” that, according to Lockheed Martin, combines malware and exploit into a deliverable payload. Most attackers usually use automated tools to generate the malware or refer to the DarkWeb to purchase the malware. More sophisticated actors or nation-sponsored APT (Advanced Persistent Threat Groups) would write their custom malware to make the malware sample unique and evade detection on the target.

 

Delivery

The Delivery phase is when “Megatron” decides to choose the method for transmitting the payload or the malware. He has plenty of options to choose from:

• Phishing email: after conducting the reconnaissance and determining the targets for the attack, the malicious actor would craft a malicious email that would target either a specific person (spearphishing attack) or multiple people in the company. The email would contain a payload or malware. For example, “Megatron” would learn that Nancy from the Sales department at company A would constantly like the posts on LinkedIn from Scott, a Service Delivery Manager at company B. He would give it a second guess that they both communicate with each other over work emails. “Megatron” would craft an email using Scott’s First Name and Last Name, making the domain look similar to the company Scott is working at. An attacker would then send a fake “Invoice” email to Nancy, which contains the payload.
• Distributing infected USB drives in public places like coffee shops, parking lots, or on the street. An attacker might decide to conduct a sophisticated USB Drop Attack by printing the company’s logo on the USB drives and mailing them to the company while pretending to be a customer sending the USB devices as a gift. You can read about one of these similar attacks at CSO Online “Cybercriminal group mails malicious USB dongles to targeted companies.”
• Watering hole attack. A watering hole attack is a targeted attack designed to aim at a specific group of people by compromising the website they are usually visiting and then redirecting them to the malicious website of an attacker’s choice. The attacker would look for a known vulnerability for the website and try to exploit it. The attacker would encourage the victims to visit the website by sending “harmless” emails pointing out the malicious URL to make the attack work more efficiently. After visiting the website, the victim would unintentionally download malware or a malicious application to their computer. This type of attack is called a drive-by download. An example can be a malicious pop-up asking to download a fake Browser extension.

Exploitation

To gain access to the system, an attacker needs to exploit the vulnerability. In this phase, “Megatron” got a little bit creative – he created two phishing emails, one that contains a phishing link to a fake Office 365 login page and another one containing a macro attachment that would execute ransomware when the victim opens it. “Megatron” successfully delivered his exploits and got two victims to click on the malicious link and open the malicious file.

The attacker might also apply a “Zero-day Exploit” in this stage. According to FireEye, “the zero-day exploit or a zero-day vulnerability is an unknown exploit in the wild that exposes a vulnerability in software or hardware and can create complicated problems well before anyone realizes something is wrong. A zero-day exploit leaves NO opportunity for detection at the beginning.”

These are examples of how an attacker carries out exploitation:

• The victim triggers the exploit by opening the email attachment or clicking on a malicious link.
• Using a zero-day exploit.
• Exploit software, hardware, or even human vulnerabilities.
• An attacker triggers the exploit for server-based vulnerabilities.

Installation

Once the attacker gets access to the system, he would want to reaccess the system if he loses the connection to it or if he got detected and got the initial access removed, or if the system is later patched. He will no longer have access to it. That is when the attacker needs to install a persistent backdoor. A persistent backdoor will let the attacker access the system he compromised in the past. You can check out the Windows Persistence Room on TryHackMe to learn how an attacker can achieve persistence on Windows.

The persistence can be achieved through:

• Installing a web shell on the webserver. A web shell is a malicious script written in web development programming languages such as ASP, PHP, or JSP used by an attacker to maintain access to the compromised system. Because of the web shell simplicity and file formatting (.php, .asp, .aspx, .jsp, etc.) can be difficult to detect and might be classified as benign. You may check out this great article released by Microsoft on various web shell attacks.
• Installing a backdoor on the victim’s machine. For example, the attacker can use Meterpreter to install a backdoor on the victim’s machine. Meterpreter is a Metasploit Framework payload that gives an interactive shell from which an attacker can interact with the victim’s machine remotely and execute the malicious code.
• Creating or modifying Windows services. This technique is known as T1543.003 on MITRE ATT&CK (MITRE ATT&CK® is a knowledge base of adversary tactics and techniques based on real-world scenarios). An attacker can create or modify the Windows services to execute the malicious scripts or payloads regularly as a part of the persistence. An attacker can use the tools like sc.exe (sc.exe lets you Create, Start, Stop, Query, or Delete any Windows Service) and Reg to modify service configurations. The attacker can also masquerade the malicious payload by using a service name that is known to be related to the Operating System or legitimate software.
• Adding the entry to the “run keys” for the malicious payload in the Registry or the Startup Folder. By doing that, the payload will execute each time the user logs in on the computer. According to MITRE ATT&CK, there is a startup folder location for individual user accounts and a system-wide startup folder that will be checked no matter what user account logs in.

You can read more about the Registry Run Keys / Startup Folder persistence on one of the MITRE ATT&CK techniques.

In this phase, the attacker can also use the Timestomping technique to avoid detection by the forensic investigator and also to make the malware appear as a part of a legitimate program. The Timestomping technique lets an attacker modify the file’s timestamps, including the modify, access, create and change times.

C & C (Command and Control)

After getting persistence and executing the malware on the victim’s machine, “Megatron” opens up the C2 (Command and Control) channel through the malware to remotely control and manipulate the victim. This term is also known as C&C or C2 Beaconing as a type of malicious communication between a C&C server and malware on the infected host. The infected host will consistently communicate with the C2 server; that is also where the beaconing term came from. 

The most common C2 channels used by adversaries nowadays:

• The protocols HTTP on port 80 and HTTPS on port 443 – this type of beaconing blends the malicious traffic with the legitimate traffic and can help the attacker evade firewalls.
• DNS (Domain Name Server). The infected machine makes constant DNS requests to the DNS server that belongs to an attacker, this type of C2 communication is also known as DNS Tunneling.

Important to note that an adversary or another compromised host can be the owner of the C2 infrastructure.

Actions and Objectives

After going through six phases of the attack, “Megatron” can finally achieve his goals, which means taking action on the original objectives. With hands-on keyboard access, the attacker can achieve the following:

• Collect the credentials from users.
• Perform privilege escalation (gaining elevated access like domain administrator access from a workstation by exploiting the misconfiguration).
• Internal reconnaissance (for example, an attacker gets to interact with internal software to find its vulnerabilities).
• Lateral movement through the company’s environment.
• Collect and exfiltrate sensitive data.
• Deleting the backups and shadow copies. Shadow Copy is a Microsoft technology that can create backup copies, snapshots of computer files, or volumes.
• Overwrite or corrupt data.

We recommend not only relying on the traditional Cyber Kill Chain model but also referring to MITRE ATT&CK as well as Unified Kill Chain to apply a more comprehensive approach to your defence methodologies.