CEH Cryptography and Malware Analysis Practice Question
A security analyst is investigating a malware incident and needs to determine whether a suspicious file is malicious. The analyst has a hash of the file and wants to quickly check if it is a known malware sample without executing it. Which action should the analyst take?
⚠ Common exam trap
The trap here is thinking that uploading the file to a public service is always necessary, when in fact a hash lookup can often provide the answer without exposing the file.
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
✓
Query the hash against an online malware hash repository such as MalwareBazaar or VirusTotal's hash search.
Querying the hash against an online malware hash repository is the fastest and safest way to check if a file is known malware. It avoids uploading the potentially sensitive file and provides immediate results from community-sourced threat intelligence. This method is ideal when the analyst only has a hash and needs a quick determination.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
Query the hash against an online malware hash repository such as MalwareBazaar or VirusTotal's hash search.
Why this is correct
Querying the hash against an online repository like MalwareBazaar or VirusTotal's hash search allows the analyst to check if the file is known malware without uploading the file itself. This preserves confidentiality and provides quick results. If the hash matches a known sample, the analyst can obtain additional information such as family, behavior, and indicators of compromise.
- ✗
Perform static analysis by disassembling the file to look for malicious code patterns.
Why it's wrong here
Static analysis via disassembly is thorough but time-consuming and requires expertise. It is not a quick check, especially when the analyst only has a hash. Moreover, if the file is packed or obfuscated, static analysis may be difficult. The analyst should first leverage existing threat intelligence via hash lookup.
- ✗
Upload the file to a public malware analysis service like VirusTotal and review the detection results.
Why it's wrong here
Uploading the file to a public service can reveal if it is known malware, but it may also expose sensitive or proprietary information. Additionally, the file might be a targeted sample not yet in the database. While useful, this action is not the best first step if the analyst only has a hash and wants to avoid sharing the file.
- ✗
Run the file in a sandbox and observe its behavior to determine if it is malicious.
Why it's wrong here
Running the file in a sandbox is a valid dynamic analysis technique, but it requires executing the malware, which carries some risk and may not be necessary if the hash is already known. It is also time-consuming compared to a simple hash lookup. The analyst's goal is a quick check, so sandboxing is not the most efficient first step.
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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 EC-Council exam blueprint
This CEH 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 CEH exam.