Unit 5: Obfuscation and Malware Forensics - Practice Quiz

INT251 — Malware Analysis And Cyber Defence 60 Questions
0 Correct 0 Wrong 60 Left
0/60

1 Which encoding scheme commonly represents binary data using letters, digits, and symbols such as + and /?

Simple encoding Easy
A. SHA-256
B. AES
C. RSA
D. Base64

2 What is a key difference between encoding and encryption?

Simple encoding Easy
A. Encryption only compresses data
B. Encoding requires a secret key
C. Encoding changes data format
D. Encryption always produces text

3 Why might malware encrypt its configuration data?

Malware encryption Easy
A. To hide readable settings
B. To increase screen resolution
C. To repair system files
D. To improve network speed

4 What is custom encoding in malware?

Custom encoding Easy
A. A Windows user authentication method
B. A hardware-based encryption feature
C. A developer-defined data transformation
D. A standard disk partition format

5 What is the main goal of malware unpacking?

Malware unpacking Easy
A. Delete all operating system logs
B. Block every network connection
C. Recover the hidden program code
D. Create a new user account

6 When is packed malware often unpacked automatically?

Malware unpacking Easy
A. When the monitor turns off
B. When a user changes wallpaper
C. When it runs in memory
D. When the disk is formatted

7 What should an analyst normally do after obtaining a memory image?

Memory forensics steps Easy
A. Install updates into the image
B. Convert the image into source code
C. Rename all running processes
D. Preserve and analyze the image

8 What does memory acquisition collect from a running computer?

Memory acquisition Easy
A. Printed paper documents
B. Contents of volatile RAM
C. Only BIOS configuration values
D. Only deleted disk sectors

9 Why should RAM usually be acquired before shutting down a suspected system?

Memory acquisition Easy
A. RAM contents are volatile
B. Shutdown expands RAM capacity
C. Shutdown creates network traffic
D. RAM contents are always encrypted

10 What is Volatility primarily used for?

Volatility overview Easy
A. Designing network cables
B. Compiling mobile applications
C. Editing digital photographs
D. Analyzing memory images

11 What does enumerating processes reveal?

Enumerating processes Easy
A. Passwords printed on labels
B. Rules configured on routers
C. Processes present in memory
D. Files stored in cloud backups

12 Which process detail is commonly useful when identifying suspicious activity?

Enumerating processes Easy
A. Keyboard layout
B. Monitor brightness
C. Printer paper size
D. Process identifier

13 What can a process handle reference in Windows?

Listing process handles Easy
A. A processor clock speed
B. A screen color profile
C. A keyboard language pack
D. An open system object

14 Why would an analyst dump a suspicious executable from memory?

Dumping executable and DLL Easy
A. To update its digital signature
B. To restart the operating system
C. To examine its recovered code
D. To increase available RAM

15 What can a list of network connections reveal during malware analysis?

Listing network connections and sockets Easy
A. Installed monitor dimensions
B. Physical room temperature
C. Remote systems contacted
D. Battery manufacturing date

16 What does a listening socket indicate?

Listing network connections and sockets Easy
A. A password was decrypted
B. A registry key was deleted
C. A file awaits compression
D. A process awaits connections

17 Why do analysts inspect the Windows Registry during malware forensics?

Inspecting registry Easy
A. To test physical network cables
B. To recover damaged monitor pixels
C. To measure processor temperature
D. To find configuration and persistence

18 Why might a malicious program install itself as a Windows service?

Investigating service Easy
A. To enlarge disk sectors
B. To run automatically
C. To calibrate the display
D. To replace the keyboard

19 What can extracted command history show an investigator?

Extracting command history Easy
A. Images viewed in a gallery
B. Packets blocked by hardware
C. Keys pressed during startup
D. Commands entered in a shell

20 What does listing DLLs for a process help identify?

Listing DLLs Easy
A. Ports available on a switch
B. Users connected to a printer
C. Folders stored in a backup
D. Libraries loaded by the process

21 A malware sample stores the string powershell.exe as cG93ZXJzaGVsbC5leGU=. Which decoding operation should an analyst try first?

Simple encoding Medium
A. Base64 decoding
B. ROT13 decoding followed by decompression
C. URL decoding
D. Hexadecimal decoding

22 An analyst discovers the bytes 68 74 74 70 3A 2F 2F in a malware configuration. What does interpreting them as ASCII reveal?

Simple encoding Medium
A. http://
B. ftp://
C. file://, indicating that the malware accesses only local files
D. https://

23 A malware executable contains a high-entropy data section that becomes readable configuration data after the sample starts. What is the most effective next action?

Malware encryption Medium
A. Search only the disk image
B. Rename the executable section
C. Assume the section contains a digitally signed library
D. Capture and inspect process memory

24 Several encrypted configuration blocks use the same stream-cipher key and nonce. Two ciphertexts are and . What does produce?

Malware encryption Medium
A.
B.
C. The original key and nonce in plaintext form
D.

25 A custom decoder processes each byte using . The encoded byte is 0x44. What is the decoded byte?

Custom encoding Medium
A. 0x40
B. 0x47, because the decoder adds the offset before applying the modulus
C. 0x41
D. 0x3F

26 A suspected custom encoding repeatedly applies XOR with a four-byte key. Which observation would most strongly support this hypothesis?

Custom encoding Medium
A. Every encoded byte is printable ASCII
B. Byte patterns repeat every four positions
C. The file has a valid PE signature
D. The executable imports many cryptographic libraries and has a valid certificate

27 During dynamic unpacking, execution leaves a small unpacking stub and enters a newly written memory region containing valid PE-like code. What should the analyst do next?

Malware unpacking Medium
A. Restart the sample and rely exclusively on static string extraction
B. Dump the unpacked region and rebuild imports
C. Delete the newly allocated memory region
D. Dump the process near the original entry point

28 Which API sequence most strongly suggests that one process is unpacking or injecting code into another process?

Malware unpacking Medium
A. GetVersionEx, GetSystemTime, Sleep, followed by normal process termination
B. OpenProcess, VirtualAllocEx, WriteProcessMemory
C. CreateFile, ReadFile, CloseHandle
D. RegOpenKey, RegQueryValue, RegCloseKey

29 After receiving a memory image, which workflow best preserves forensic reliability before detailed analysis?

Memory forensics steps Medium
A. Hash the image, preserve the original, and analyze a copy
B. Upload the only available image to several public analysis services
C. Compress the image, execute it, and record the output
D. Modify the image, identify malware, and calculate a hash

30 A responder must acquire RAM from a running compromised server. Which approach is most appropriate?

Memory acquisition Medium
A. Use a trusted acquisition tool and hash the output
B. Install multiple diagnostic suites before acquisition
C. Run the suspected malware again so that all indicators become visible
D. Shut down the server and copy the page file

31 Why should a responder document the acquisition tool, command, time, and output hash when collecting memory?

Memory acquisition Medium
A. To increase the memory image size
B. To support integrity and chain of custody
C. To remove malware from captured RAM
D. To guarantee that every encrypted memory page is automatically decrypted

32 A Volatility plugin produces invalid addresses and implausible process results. What should the analyst verify first?

Volatility overview Medium
A. Whether the memory image was renamed with a .raw extension
B. The image format and symbol or profile selection
C. The disk partition's volume label
D. The browser version on the host

33 A process appears in a Volatility psscan result but not in pslist. Which interpretation is most appropriate?

Enumerating processes Medium
A. It is certainly a duplicate process entry
B. It proves that the memory acquisition tool encrypted the process table
C. It must be a normal kernel process
D. It may be terminated or hidden from active lists

34 The process tree shows winword.exe spawning powershell.exe, which then launches rundll32.exe. Why is this chain suspicious?

Enumerating processes Medium
A. It resembles document-based script execution
B. Every use of rundll32.exe confirms that the Windows installation is corrupted
C. PowerShell cannot create child processes
D. Office applications commonly compile device drivers

35 A suspicious process has an open handle to \Device\PhysicalMemory and several handles to security-related processes. What does this most directly justify?

Listing process handles Medium
A. Treating it as a harmless text editor
B. Deleting all handles from the memory image
C. Concluding that it is legitimate because physical-memory access is required by every process
D. Examining its privileges and access activity

36 An analyst finds a suspicious process whose executable no longer exists on disk. What is the best memory-forensics action?

Dumping executable and DLL Medium
A. Export the registry and assume it contains the complete executable
B. Dump the process executable from memory
C. Reboot the system to recreate the file
D. Recover it only from browser cache

37 Volatility reports an established TCP connection from PID 2480 to an unfamiliar external address on port 443. What is the most useful next correlation?

Listing network connections and sockets Medium
A. Inspect only the local keyboard layout and desktop wallpaper settings
B. Change the remote address in the memory image
C. Map PID 2480 to its process and command line
D. Assume port 443 makes the connection benign

38 A memory-resident registry value under Software\Microsoft\Windows\CurrentVersion\Run launches an executable from a user's temporary directory. What behavior does this most likely indicate?

Inspecting registry Medium
A. DNS cache poisoning
B. Persistence at user logon
C. Kernel memory compression
D. Automatic repair of missing Windows system files during startup

39 A service discovered in memory has an automatic start type, a random-looking name, and an executable path inside C:\Users\Public. What is the best assessment?

Investigating service Medium
A. It is safe because the path is writable
B. It is normal because all services use random names
C. It is suspicious and may provide persistence
D. It is a standard Windows service installed in the default protected system directory

40 Recovered console history contains whoami, net user, and ipconfig /all, followed by a download command. What does this sequence most likely represent?

Extracting command history Medium
A. Registry hive repair followed by memory compression
B. Routine disk defragmentation and file indexing
C. System reconnaissance followed by payload retrieval
D. A complete operating-system upgrade performed through the graphical interface

41 A memory buffer begins with TVqQAAMAAAAEAAAA, while the corresponding file is absent from disk. Which action most directly tests whether this is a simply encoded Windows executable?

Simple encoding Hard
A. Hex-decode the buffer and check for a PE header
B. XOR the buffer with 0xFF and check for an MZ header
C. ROT13-decode the buffer and check for a DOS header
D. Base64-decode the buffer and check for an MZ header

42 An analyst finds a Base64-looking PowerShell argument whose length is valid, but ordinary Base64 decoding produces alternating printable characters and null bytes. What is the most likely explanation?

Simple encoding Hard
A. The decoded content is UTF-16LE text
B. The encoded content uses a rolling XOR key
C. The decoded content is a compressed PE image
D. The encoded content uses an AES block mode

43 Two encrypted configuration blobs from separate infections have identical 16-byte prefixes but different later blocks. Both plaintexts are believed to begin with the same JSON header. Which implementation flaw is most strongly indicated?

Malware encryption Hard
A. CTR encryption uses random nonces
B. CBC encryption reuses a fixed IV
C. RSA encryption applies randomized padding
D. GCM encryption rotates authentication tags

44 A malware sample decrypts strings by XORing ciphertext with the output of a deterministic pseudorandom generator seeded from a constant. Why can this behave like a reusable stream cipher weakness?

Malware encryption Hard
A. The ciphertext automatically reveals the seed
B. The generator converts XOR into substitution
C. The same keystream encrypts every string
D. The constant seed disables ciphertext entropy

45 A decoder transforms each byte using , where is the zero-based position. Which operation correctly reconstructs plaintext byte ?

Custom encoding Hard
A. Subtract modulo 256, then XOR with
B. Subtract modulo 256, then XOR with
C. Add modulo 256, then XOR with
D. XOR with , then subtract modulo 256

46 A suspected custom decoder reads one input byte, emits two output nibbles through a lookup table, and rejects symbols outside a 16-character alphabet. Which artifact is most useful for reconstructing the encoding without executing the malware?

Custom encoding Hard
A. The mutex name and process command line
B. The alphabet and nibble-combination logic
C. The import table and section permissions
D. The timestamp and linker version fields

47 During dynamic unpacking, execution leaves a small loader stub and reaches a newly writable-then-executable region containing coherent PE code. What is the best point to dump the process image?

Malware unpacking Hard
A. Before the loader allocates its destination region
B. Immediately after the packed process is created
C. After the payload terminates and memory is released
D. After unpacking completes and before payload execution

48 A dumped unpacked PE contains valid code and sections but fails because its imports point into addresses resolved in the original process. What post-processing is primarily required?

Malware unpacking Hard
A. Recalculate the DOS stub checksum
B. Rebuild the import address table
C. Replace the resource directory tree
D. Restore the original overlay bytes

49 A responder has one RAM image and suspects process injection. Which workflow best preserves evidentiary integrity while minimizing premature conclusions?

Memory forensics steps Hard
A. Scan injected regions, choose a profile, then hash the image
B. Dump suspicious processes, modify metadata, then record hashes
C. Search strings, delete duplicates, then enumerate active processes
D. Hash the image, identify context, enumerate, then inspect anomalies

50 A Windows host uses full-disk encryption, and malware is believed to keep its configuration only in memory. Why should live RAM acquisition generally precede shutdown?

Memory acquisition Hard
A. Shutdown preserves RAM but clears encrypted disk sectors
B. Shutdown destroys volatile data and may relock storage
C. RAM acquisition prevents all malware from altering evidence
D. RAM acquisition automatically decrypts every protected file

51 An acquisition tool can write a RAM image either to the suspect system disk or to a prepared external device. Assuming both methods work, which choice usually has the lower evidence impact?

Memory acquisition Hard
A. Write to the external device and document tool effects
B. Write to the page file and export it after shutdown
C. Write to the system disk and preserve file timestamps
D. Write to process memory and recover it during analysis

52 A Volatility 3 analysis fails because an exact Windows symbol table is unavailable locally. Which statement best describes the appropriate next step?

Volatility overview Hard
A. Patch the image header to match an installed symbol table
B. Select a Volatility 2 profile with a similar service pack
C. Use Linux banners to infer the Windows kernel structures
D. Obtain matching symbols using the image's kernel identifiers

53 On a Windows image, a process appears in a pool scan but not in the active process list. Which conclusion is most defensible without additional evidence?

Enumerating processes Hard
A. It may be terminated, hidden, or a stale allocation
B. It is certainly running without an EPROCESS object
C. It is certainly hidden by a kernel rootkit
D. It must have been created after memory acquisition

54 A process has parent PID 900, but PID 900 was created ten minutes after the child. Which interpretation should an analyst prioritize?

Enumerating processes Hard
A. The process list is invalid and should be discarded
B. PID reuse or manipulated parentage requires correlation
C. The parent must have existed before its recorded creation
D. The child necessarily altered the system clock

55 A suspicious process has a handle to \Device\PhysicalMemory with powerful access rights. Why is this more significant than merely finding the object name as a string?

Listing process handles Hard
A. The string identifies the exact granted access mask
B. The string proves the object was opened and later closed
C. The handle links the process to an open kernel object
D. The handle proves the process modified every physical page

56 A memory-dumped DLL has correct executable code but differs substantially from the on-disk file. Which factor most complicates direct hash comparison?

Dumping executable and DLL Hard
A. Windows encrypts all executable sections after loading
B. Relocations and loader-resolved imports modify memory pages
C. The DOS signature is removed from every loaded DLL
D. Memory acquisition reverses each section's byte order

57 A pool scan finds a TCP endpoint owned by a process that has already exited, but the endpoint is absent from the active connection listing. What is the strongest interpretation?

Listing network connections and sockets Hard
A. It is invalid because exited processes leave no pool data
B. It is a residual artifact requiring timestamp correlation
C. It proves the remote host erased the local socket
D. It proves an active connection hidden by the process

58 A memory-resident registry hive shows a malicious Run-key value that is absent from the corresponding hive file collected after shutdown. Which explanation best fits both observations?

Inspecting registry Hard
A. Memory acquisition converts volatile keys into persistent keys
B. The disk hive parser automatically removes Run-key values
C. Registry values exist in RAM only when digitally signed
D. The in-memory hive had unflushed or later-removed changes

59 A service registry entry names svchost.exe, but memory analysis shows its service DLL loaded from a user-writable directory. Which artifact most directly identifies the payload configured for that shared-host service?

Investigating service Hard
A. The SCM database file's creation timestamp
B. The svchost.exe DOS-header checksum field
C. The service process's preferred base address
D. The service's Parameters\ServiceDll registry value

60 Memory analysis recovers a console command from a history buffer, but no matching process is currently active. What is the most accurate evidentiary interpretation?

Extracting command history Hard
A. It indicates entered text, not necessarily successful execution
B. It indicates the command was typed after acquisition ended
C. It proves the command completed with administrator privileges
D. It proves the command created no child process or output