220-1202 Malware Types and Removal — 15 Questions

Question 1

During a routine security audit, a technician discovers that a user's workstation has a program that records keystrokes and periodically sends the data to an external server. The user denies installing any software recently. Which type of malware is this?

Accepted Answer

Keylogger. A keylogger is a type of spyware that records keystrokes to capture sensitive information like passwords. It often operates stealthily without the user's knowledge, matching the scenario where the user did not install anything. Spyware is the broader category, but keylogger is the specific variant described.

Answer

Trojan horse

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Worm

Answer

Ransomware

Question 2

A technician is investigating a security incident where multiple workstations on the same network are showing signs of infection: slow performance, unusual network traffic, and the presence of a file named 'svch0st.exe' in the Startup folder. The technician suspects a worm that spreads through network shares. What is the most effective containment strategy?

Accepted Answer

Disable network shares and isolate infected workstations from the network.. A worm that spreads via network shares requires immediate network segmentation to stop propagation. Disabling the network shares on all workstations and isolating infected systems from the network prevents the worm from reaching other devices. Patching the vulnerability used for spread (e.g., SMB) is also critical, but containment is the priority.

Answer

Run a full antivirus scan on all workstations simultaneously.

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Update the antivirus definitions on one workstation and scan it.

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Reboot all workstations into Safe Mode with Networking.

Question 3

A technician is tasked with removing a persistent malware infection that survives reboots and re-infects the system even after a full antivirus scan in Safe Mode. The malware appears to hide in the Master Boot Record (MBR). Which removal method should the technician use?

Accepted Answer

Use the Windows Recovery Environment to run bootrec /fixmbr.. MBR malware infects the boot sector, loading before the operating system, which allows it to survive standard scans and Safe Mode. The most effective removal is to use the Windows Recovery Environment (WinRE) with bootrec /fixmbr and bootrec /fixboot commands. This overwrites the infected boot sector. If that fails, a full reinstall may be necessary.

Answer

Run a system file checker (sfc /scannow) from within Windows.

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Perform a clean installation of Windows without formatting the drive.

Answer

Disable System Restore and delete all restore points.

Question 4

A small business owner calls for support because all of their files on the server have been renamed with a .encrypted extension, and a text file named 'README_TO_DECRYPT.txt' appears on the desktop demanding a Bitcoin payment. What is the first step the technician should take?

Accepted Answer

Disconnect the server from the network.. The first step in a ransomware incident is to isolate the infected system from the network to prevent the malware from spreading to other devices. Paying the ransom is discouraged as it does not guarantee data recovery and funds criminal activity. After isolation, the technician can assess the damage and attempt recovery from backups.

Answer

Pay the ransom to get the decryption key immediately.

Answer

Run a full antivirus scan on the server.

Answer

Restore files from a recent backup immediately.

Question 5

A technician is dealing with a zero-day malware infection that has evaded all signature-based antivirus scans. The malware is polymorphic, changing its code each time it infects a new system. Which approach is most likely to detect and remove this type of malware?

Accepted Answer

Employ a heuristic-based or behavior-based malware removal tool.. Polymorphic malware changes its signature, making signature-based detection ineffective. Heuristic analysis and behavior-based detection tools, such as those used by advanced endpoint detection and response (EDR) solutions, can identify malware based on suspicious actions rather than static signatures. Running a tool that uses heuristic scanning can detect the malware's behavior, such as file encryption or unauthorized registry changes.

Answer

Update the antivirus to the latest signature definitions and run a full scan.

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Use a bootable antivirus rescue disk to scan the system before the OS loads.

Answer

Reinstall the operating system from a known-good backup.

Question 6

A user reports that their computer is infected with a virus and they have been trying to remove it using a free online scanner, but the problem persists. The technician suspects the malware may have disabled the antivirus software. Which safe mode should the technician use to run a full system scan?

Accepted Answer

Safe Mode with Networking. Safe Mode with Networking allows the technician to boot with minimal drivers and services while still having network access to download updated antivirus definitions or removal tools. Safe Mode alone does not provide network access, which is often needed to get the latest malware signatures. This mode also prevents many malware variants from loading, making removal easier.

Answer

Safe Mode

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Safe Mode with Command Prompt

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Last Known Good Configuration

Question 7

A user reports that their system is running very slowly, and they see frequent pop-up ads even when no browser is open. They also notice that their default search engine has changed without their permission. Which type of malware is most likely causing these symptoms?

Accepted Answer

Adware. Adware is designed to display unwanted advertisements and can modify browser settings, causing pop-ups and search engine hijacking. Unlike a virus or worm, adware does not typically replicate itself or require a host file to spread. The symptoms described—pop-ups outside the browser and unauthorized search engine changes—are classic signs of adware infection.

Answer

Virus

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Ransomware

Answer

Rootkit

Question 8

A user reports that their computer has been acting strangely: files are missing, and the mouse cursor moves on its own, opening programs and typing messages. The technician suspects a remote access Trojan (RAT). What is the most effective immediate action to stop the unauthorized access?

Accepted Answer

Disconnect the Ethernet cable and disable Wi-Fi.. A RAT gives an attacker remote control of the system. The immediate action is to disconnect the computer from the network, which cuts off the attacker's connection. After isolation, the technician can run scans and remove the malware. Continuing to work while connected risks data theft or further damage.

Answer

Run a full antivirus scan while the user is logged off.

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Change the user's password and log off.

Answer

Restore the system to a previous restore point.

Question 9

A technician is troubleshooting a Windows 10 workstation that displays a fake security alert claiming the system is infected and prompting the user to call a toll-free number. The user cannot close the alert window or open Task Manager. Which type of malware is causing this behavior, and what is the best removal approach?

Accepted Answer

It is a tech support scam; boot into Safe Mode with Networking and run an anti-malware scan.. This is a classic tech support scam, a form of scareware that locks the browser or desktop to trick users into calling a fake support number. The best removal approach is to boot into Safe Mode with Networking, then run a malware removal tool like Malwarebytes. This bypasses the malware's ability to block Task Manager and allows the technician to clean the system.

Answer

It is a rootkit; use a rootkit removal tool from within Windows.

Answer

It is ransomware; pay the fee to remove the alert.

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It is a worm; disconnect the network and reinstall the operating system.

Question 10

A technician is removing malware from a Windows 10 PC and wants to ensure that no remnants remain in the registry or startup folders. After running an antivirus scan and deleting infected files, which additional step should the technician perform?

Accepted Answer

Check and clean startup entries using MSConfig or Autoruns.. After removing malware, it is critical to check and clean startup entries using tools like MSConfig or Autoruns to prevent the malware from reloading on reboot. Malware often adds entries to the registry Run keys or the Startup folder to persist. Simply deleting files may leave these entries intact, allowing the malware to reinstall itself.

Answer

Run the Windows Memory Diagnostic tool.

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Disable System Restore to free up disk space.

Answer

Update all device drivers to the latest versions.

Question 11

A user reports that their web browser's homepage has changed to an unfamiliar search engine, and new toolbars have appeared without their consent. They have not installed any new software recently. Which type of malware is most likely responsible?

Accepted Answer

Browser hijacker. A browser hijacker modifies browser settings like the homepage and adds unwanted toolbars. It often installs silently through drive-by downloads or bundled with other software. Removal requires resetting the browser and scanning with anti-malware tools.

Answer

Trojan horse

Answer

Worm

Answer

Ransomware

Question 12

A customer reports that their desktop computer is running extremely slowly, and they see frequent pop-up advertisements even when no browser is open. Task Manager shows a process named 'svch0st.exe' consuming 95% CPU. Which type of malware is most likely causing these symptoms?

Accepted Answer

Adware. Adware displays unwanted advertisements and often masquerades as legitimate processes. The misspelled 'svch0st.exe' mimics a Windows system process, a common adware tactic. This malware type is best removed using a dedicated anti-malware tool.

Answer

Ransomware

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Rootkit

Answer

Spyware

Question 13

A small business owner reports that all their Microsoft Office documents are now encrypted with a '.crypt' extension and a ransom note demands payment in cryptocurrency. They have a backup from last week stored on an external drive that was disconnected after the backup. What is the best recovery strategy?

Accepted Answer

Restore the files from the disconnected external backup after removing the malware.. Since the backup is offline and not encrypted, restoring from it is the safest and most reliable recovery method. Paying the ransom is discouraged as it funds criminals and may not work. The system should be cleaned of malware before restoration.

Answer

Pay the ransom to obtain the decryption key.

Answer

Run a decryptor tool downloaded from a random website.

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Use System Restore to revert the system to a previous state.

Question 14

A technician is investigating a security breach where sensitive customer data was exfiltrated. The only malware found is a hidden driver that intercepts keystrokes and sends them to a remote server. Which malware type is responsible, and what is the best removal strategy?

Accepted Answer

Keylogger; use a rescue disk to boot and run an anti-rootkit scanner.. A keylogger records keystrokes to steal credentials and sensitive data. As a kernel-level rootkit, it hides from standard scans. Booting from a rescue disk and using a specialized anti-rootkit tool is necessary to remove it without reinstalling the OS.

Answer

Spyware; remove by running a standard antivirus scan.

Answer

Ransomware; restore from backup.

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Adware; uninstall suspicious programs from Control Panel.

Question 15

During a routine security audit, a technician discovers that a user's computer has a program that opens a backdoor on port 4444 and allows remote control. The program was installed alongside a free PDF converter the user downloaded last week. Which malware type is this, and what is the most effective removal method?

Accepted Answer

Trojan horse; boot into Safe Mode and run a full anti-malware scan.. A Trojan horse disguises as legitimate software (the PDF converter) but contains malicious code. This Trojan opens a backdoor (a RAT). Removal requires disconnecting from the network, booting into Safe Mode, and using an updated anti-malware scanner to eliminate the Trojan and its persistence mechanisms.

Answer

Worm; use a network-based firewall to block port 4444.

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Ransomware; pay the ransom to regain control.

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Rootkit; perform a clean installation of Windows.