Stuxnet is the malware signature of the suspicious file in the above scenario. Malware is malicious software that can harm or compromise the security or functionality of a system or network. Malware can include various types, such as viruses, worms, trojans, ransomware, spyware, etc. Malware signature is a unique pattern or characteristic that identifies a specific malware or malware family. Malware signature can be used to detect or analyze malware by comparing it with known malware signatures in databases or repositories. To analyze the suspicious file and identify the malware signature, one has to follow these steps:

Navigate to Documents folder of Attacker Machine-1.

Right-click on security_update.exe file and select Scan with VirusTotal option.

Wait for VirusTotal to scan the file and display the results.

Observe the detection ratio and details.

The detection ratio is 59/70, which means that 59 out of 70 antivirus engines detected the file as malicious. The details show that most antivirus engines detected the file as Stuxnet, which is a malware signature of a worm that targets industrial control systems (ICS). Stuxnet can be used to sabotage or damage ICS by modifying their code or behavior. Therefore, Stuxnet is the malware signature of the suspicious file. KLEZ is a malware signature of a worm that spreads via email and network shares. KLEZ can be used to infect or overwrite files, disable antivirus software, or display fake messages. ZEUS is a malware signature of a trojan that targets banking and financial systems. ZEUS can be used to steal or modify banking credentials, perform fraudulent transactions, or install other malware. Conficker is a malware signature of a worm that exploits a vulnerability in Windows operating systems. Conficker can be used to create a botnet, disable security services, or download other malware

Security event log is the type of event log analyzed by Tenda in the above scenario. Windows Event Viewer is a tool that displays logged data about various events that occur on a Windows system or network. Windows Event Viewer categorizes event logs into different types based on their source and purpose. Security event log is the type of event log that records events related to Windows security; specifically, log-on/log-off activities, resource access, and also information based on Windows system's audit policies . Security event log can help identify attempted or successful unauthorized activities on a Windows system or network. Application event log is the type of event log that records events related to applications running on a Windows system, such as errors, warnings, or information messages. Setup event log is the type of event log that records events related to the installation or removal of software or hardware components on a Windows system. System event log is the type of event log that records events related to the operation of a Windows system or its components, such as drivers, services, processes, etc.

Quid pro quo is the social engineering technique that Johnson employed in the above scenario. Social engineering is a technique that involves manipulating or deceiving people into performing actions or revealing information that can be used for malicious purposes. Social engineering can be performed through various methods, such as phone calls, emails, websites, etc. Quid pro quo is a social engineering method that involves offering a service or a benefit in exchange for information or access. Quid pro quo can be used to trick victims into believing that they are receiving help or assistance from a legitimate source, while in fact they are compromising their security or privacy . In the scenario, Johnson performed quid pro quo by claiming himself to represent a technical support team from a vendor and offering to help sibertech.org with a server issue, while in fact he prompted the victim to execute unusual commands and install malicious files, which were then used to collect and pass critical information to Johnson's machine. Diversion theft is a social engineering method that involves diverting the delivery or shipment of goods or assets to a different location or destination. Elicitation is a social engineering method that involves extracting information from a target by engaging them in a conversation or an interaction. Phishing is a social engineering method that involves sending fraudulent emails or messages that appear to come from a trusted source, such as a bank, a company, or a person, and asking the recipient to click on a link, open an attachment, or provide personal or financial information.

Non-routing dual-homed hosts are the type of bastion hosts configured by Elliott in the above scenario. A bastion host is a system or device that is exposed to the public internet and acts as a gateway or a proxy for other systems or networks behind it. A bastion host can be used to provide an additional layer of security and protection for internal systems or networks from external threats and attacks . A bastion host can have different types based on its configuration or functionality. A non-routing dual-homed host is a type of bastion host that has two network interfaces: one connected to the public internet and one connected to the internal network. A non-routing dual-homed host does not allow any direct communication between the two networks and only allows specific services or applications to pass through it . A non-routing dual-homed host can be used to isolate and secure internal systems or networks from external access . In the scenario, Elliott was appointed to test a newly developed application deployed over an organizational network using a bastion host. Elliott initiated the process by configuring the non-reusable bastion host. He then tested the newly developed application to identify the presence of security flaws that were not yet known; further, he executed services that were not secure. This means that he configured a non-routing dual-homed host for this purpose. An external services host is a type of bastion host that provides external services, such as web, email, FTP, etc., to the public internet while protecting internal systems or networks from direct access . A victim machine is not a type of bastion host, but a term that describes a system or device that has been compromised or infected by an attacker or malware . A one-box firewall is not a type of bastion host, but a term that describes a firewall that performs both packet filtering and application proxy functions in one device .

Eradication is the IH&R step performed by Fernando in this scenario. Eradication is a step in IH&R that involves eliminating the root cause of the incident and closing all attack vectors to prevent similar incidents in future. Eradication can include applying patches, installing security mechanisms, removing malware, restoring backups, or reformatting systems.