GrayKey is the correct choice because it is the dedicated mobile forensic tool that leverages the checkm8 bootrom exploit (CVE-2019-15971) to perform physical extraction on iOS devices. The checkm8 exploit is unpatchable in hardware, allowing GrayKey to bypass the device’s security enclave and extract a full file system image, including encrypted data, from iPhones up to the iPhone X. On the Computer Hacking Forensic Investigator CHFI exam, this question tests your knowledge of specialized forensic hardware versus software-only methods; a common trap is confusing GrayKey with Cellebrite, which relies on different vulnerabilities or user passcode bypass techniques. Remember that GrayKey’s unique advantage is its use of a bootrom-level exploit that cannot be fixed by a software update, making it the go-to tool for deep iOS forensics. A helpful memory tip: think “GrayKey = Gray (hardware) + Key (bootrom unlock)” to recall its unpatchable physical extraction capability.
CHFI Mobile and Malware Forensics Practice Question
This CHFI practice question tests your understanding of mobile and malware forensics. Read the scenario carefully and evaluate each option against the stated constraints before committing to an answer. After answering, compare your reasoning against the explanation and wrong-answer breakdown below. Once you have made your selection, read the full explanation to reinforce the concept and understand why each distractor is designed to mislead on exam day.
Which mobile forensic tool is commonly used for physical extraction of iOS devices via checkm8 exploit?
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
GrayKey
GrayKey is correct because it is a dedicated forensic tool that leverages the checkm8 bootrom exploit (CVE-2019-15971) to perform physical extraction on iOS devices. The checkm8 exploit is unpatchable in hardware, allowing GrayKey to bypass the device's security enclave and extract a full file system image, including encrypted data, from iPhones up to the iPhone X.
Key principle: Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
✓
GrayKey
Why this is correct
GrayKey is specifically designed to use the checkm8 exploit for physical extraction.
Related concept
Read the scenario before looking for a memorised answer.
✗
Cellebrite UFED
Why it's wrong here
Cellebrite UFED can perform physical extraction but typically uses different exploits or methods.
✗
Magnet AXIOM
Why it's wrong here
Magnet AXIOM is a forensic analysis platform that integrates with various tools but does not perform physical extraction directly.
✗
Oxygen Forensic Detective
Why it's wrong here
Oxygen Forensic Detective is a software suite that supports logical and file system extraction but not typically physical via checkm8.
Common exam traps
Common exam trap: answer the scenario, not the keyword
EC-Council often tests the misconception that Cellebrite UFED is the primary tool for all mobile extractions, but the trap here is that checkm8 is a specific hardware-level exploit unique to GrayKey, not a general feature of commercial forensic suites.
Detailed technical explanation
How to think about this question
The checkm8 exploit targets a vulnerability in the BootROM (SecureROM) of Apple's A5 through A11 chips, allowing arbitrary code execution before the device's secure boot chain initializes. This enables a physical extraction by dumping the device's NAND flash memory via USB in DFU mode, bypassing passcode and encryption keys stored in the Secure Enclave. In real-world scenarios, GrayKey is often used by law enforcement to access locked iPhones, but the exploit is limited to devices with vulnerable BootROM versions (e.g., iPhone 4S through X).
KKey Concepts to Remember
Read the scenario before looking for a memorised answer.
Find the constraint that changes the correct option.
Eliminate answers that are true in general but not in this case.
TExam Day Tips
→Watch for words such as best, first, most likely and least administrative effort.
→Review why wrong options are wrong, not only why the correct option is correct.
Key takeaway
Answer the scenario, not the keyword: identify the specific constraint before choosing the most familiar-sounding option.
Real-world example
How this comes up in practice
A small business has 20 workstations on the 192.168.1.0/24 network and one public IP from its ISP. The router uses PAT (NAT overload) so all 20 devices share one public address using different source ports. NAT questions test whether you understand the four address terms and which direction each translation applies.
Related glossary terms
Concepts from this question explained
These glossary pages explain the core terms tested in this CHFI question in full detail.
Mobile and Malware Forensics — This question tests Mobile and Malware Forensics — Read the scenario before looking for a memorised answer..
What is the correct answer to this question?
The correct answer is: GrayKey — GrayKey is correct because it is a dedicated forensic tool that leverages the checkm8 bootrom exploit (CVE-2019-15971) to perform physical extraction on iOS devices. The checkm8 exploit is unpatchable in hardware, allowing GrayKey to bypass the device's security enclave and extract a full file system image, including encrypted data, from iPhones up to the iPhone X.
What should I do if I get this CHFI question wrong?
Identify which exam domain this question belongs to, review the core concept, then practise similar questions from the same domain.
What is the key concept behind this question?
Read the scenario before looking for a memorised answer.
About these practice questions
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Variation 1. Which mobile forensic tool is commonly used to perform a physical extraction of an iOS device, including bypassing the lock screen on certain models?
easy
A.Magnet AXIOM
✓ B.GrayKey
C.Oxygen Forensic Detective
D.FTK Imager
Why B: GrayKey is a specialized hardware tool designed by Grayshift that performs physical extraction of iOS devices, including bypassing the lock screen on certain models (e.g., iPhone 5 through iPhone X) by exploiting bootrom vulnerabilities or using brute-force techniques. It is widely used in law enforcement for forensic acquisition of iOS devices where logical extraction is insufficient.
Last reviewed: Jun 30, 2026
Question Discussion
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This CHFI practice question is part of Courseiva's free EC-Council 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 CHFI exam.
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