GPEN Advanced Password Attacks Practice Question
A penetration tester has captured a NetNTLMv2 challenge-response hash from a Windows workstation over SMB. The tester plans to recover the plaintext password offline using Hashcat on a workstation with a dedicated GPU. The hash file is saved as 'capture.txt' in the format 'username::domain:challenge:response:blob'. Which Hashcat mode should the tester specify to correctly crack this hash?
⚠ Common exam trap
It's easy for candidates to confuse NetNTLMv2 with NTLM or NetNTLMv1, leading to selection of the wrong Hashcat mode.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Hashcat mode 5600
The captured hash is a NetNTLMv2 challenge-response, which requires Hashcat mode 5600. This mode correctly emulates the NetNTLMv2 protocol, allowing the GPU to compute the HMAC-MD5 response for each password candidate. Other modes target different hash types such as NTLM, NetNTLMv1, or LM, and will not parse or crack the hash. Therefore, mode 5600 is the only correct choice for this scenario.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Hashcat mode 5500
Why it's wrong here
Mode 5500 is used for NetNTLMv1 hashes, which use a weaker challenge-response mechanism. NetNTLMv2 incorporates a variable client challenge and HMAC-MD5, requiring a different cracking approach. Specifying mode 5500 for a NetNTLMv2 hash will not correctly parse the input and will fail to crack the password, as the algorithms do not match.
- ✓
Hashcat mode 5600
Why this is correct
Hashcat mode 5600 is specifically designed for NetNTLMv2 hashes. The captured format matches the expected input for this mode, allowing the GPU to efficiently compute HMAC-MD5 responses. Using this mode ensures the challenge-response mechanism is properly emulated, enabling successful recovery of the plaintext password. Other modes target different hash types and will fail to parse or crack the hash correctly.
- ✗
Hashcat mode 1000
Why it's wrong here
Mode 1000 is for NTLM hashes, which are unsalted MD4 hashes of the password. NetNTLMv2 is a challenge-response protocol that includes a server challenge and client response, making it incompatible with mode 1000. Attempting to crack a NetNTLMv2 hash with mode 1000 will result in an error or no matches because the hash structures are fundamentally different.
- ✗
Hashcat mode 3000
Why it's wrong here
Mode 3000 is for LM hashes, an outdated and weak hashing algorithm. LM hashes are not used in NetNTLMv2 authentication and have a completely different structure. Using mode 3000 on a NetNTLMv2 capture will not work because the hash format is incompatible, and the cracking process will not yield the correct password.
About these practice questions
This GPEN question is part of Courseiva's 298-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official GIAC exam blueprint
This GPEN practice question is part of Courseiva's free GIAC certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the GPEN exam.