Computer Hacking Forensic Investigator CHFI (CHFI) — Questions 301–375

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Option A is wrong because `conv=noerror,sync` does not perform hashing; hashing is done separately with options like `hash=md5` or via a pipe to `sha256sum`. Option B is wrong because synchronous writing is controlled by the `oflag=sync` or `conv=fsync` option, not `conv=noerror,sync`; the `sync` in `conv` refers to padding with zeros, not write synchronization. Option C is wrong because `dd` does not compress data; compression requires piping through `gzip` or using `conv=lz4` or similar, and `conv=noerror,sync` has no compression effect.

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Option A is wrong because PEiD is a static analysis tool that detects packers, cryptors, and compilers in PE files by scanning file signatures; it does not execute malware or log runtime behavior. Option B is wrong because IDA Pro is a disassembler and debugger used for static and interactive reverse engineering of binary code, not for automated dynamic analysis in an isolated sandbox environment. Option C is wrong because Ghidra is a reverse engineering framework developed by the NSA that focuses on static analysis and decompilation, lacking the sandboxed execution and behavior logging capabilities of a dedicated dynamic analysis tool like Cuckoo.

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Option A is wrong because using a write blocker preserves the integrity of the source drive during acquisition, but it does not establish or document the chain of custody for the acquired image; chain of custody requires tracking who handled the evidence and verifying its integrity after acquisition. Option C is wrong because documenting every person who handled the evidence is a necessary part of chain of custody, but it does not by itself ensure the integrity of the evidence; without a cryptographic hash, a handler could tamper with the image and the documentation alone would not detect it. Option D is wrong because placing evidence in a bag and locking it in a secure room is a physical security measure that prevents unauthorized access, but it does not provide a verifiable, mathematical proof of integrity; if the evidence is later removed and replaced, physical security alone cannot prove the original data was unchanged.

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Option A is wrong because clearing battery logs is precisely what the command does, and while those logs may contain evidence of app activity, the purpose of the command is to reset them, not to preserve them; the question asks for the 'most likely purpose' in a forensic context, which is that it is destructive. Option C is wrong because the command does not affect the device's power state; it only resets battery statistics data, and ensuring a low-power state is achieved through other means like disabling radios or using airplane mode. Option D is wrong because the command does not optimize device performance during imaging; it only clears battery stats, and performance optimization is irrelevant to forensic acquisition.

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Option A is wrong because a certification alone does not guarantee that the court will accept the testimony; the court must assess whether the witness's actual knowledge and experience will assist the trier of fact, and certifications are not a substitute for demonstrated competence. Option B is wrong because published articles in peer-reviewed journals are a factor under the Daubert standard but are not the most important qualification; the witness must still show that their expertise directly aids the court in understanding the evidence. Option D is wrong because 10 years of employment as a forensic analyst does not automatically qualify someone as an expert; the court evaluates the substance of their experience and whether it logically applies to the specific digital evidence in question.

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Option A is wrong because Volatility is a memory forensics framework used for analyzing RAM dumps, not for parsing email headers or tracking email paths. Option B is wrong because Wireshark is a network protocol analyzer that captures and inspects live network traffic (e.g., SMTP packets), but it does not parse stored email headers or extract metadata like originating IP from an email's header fields. Option D is wrong because FTK Imager is a disk imaging and data acquisition tool used for creating forensic images of storage media, not for analyzing email headers or extracting email metadata.

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Option A is wrong because a man-in-the-middle attack would involve intercepting or modifying traffic between two parties, not repeated failed login attempts; there is no evidence of ARP spoofing, session hijacking, or traffic redirection in the log. Option B is wrong because SQL injection attacks target web application databases via malicious SQL queries in input fields, not SSH authentication logs; the log shows no SQL syntax or database error messages. Option C is wrong because a Denial of Service attack aims to overwhelm a service with traffic to cause disruption, not to repeatedly attempt authentication; the log shows sequential login failures without a flood of packets or resource exhaustion indicators.

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Option B (File system extraction) is wrong because it only retrieves allocated files and metadata from the mounted file system, missing deleted records that reside in unallocated space or SQLite free pages. Option C (Logical extraction via ADB) is wrong because ADB backup or content provider queries only export active data and cannot access deleted rows or unallocated clusters. Option D (Manual extraction via device UI) is wrong because the user interface only displays current application data and provides no mechanism to recover deleted database entries.

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Option B is wrong because command and control communication involves network traffic to an external server (e.g., HTTP, DNS, or IRC), not a local registry modification. Option C is wrong because anti-forensic techniques like timestomping alter file timestamps (e.g., using SetFileTime or touch), not registry keys. Option D is wrong because privilege escalation attempts typically target security tokens or exploit vulnerabilities to gain higher access (e.g., SeDebugPrivilege or UAC bypass), not setting a user-level Run key.

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Option A is wrong because /etc/gshadow stores hashed group passwords and group administrator information, not user passwords. Option B is wrong because /etc/group defines group memberships and optionally group passwords (often stored as 'x' with hashes in /etc/gshadow), not user password hashes. Option C is wrong because /etc/passwd historically stored password hashes, but modern Linux systems use shadow passwords, and /etc/passwd now contains only a placeholder (e.g., 'x') indicating the hash is in /etc/shadow.

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Option A is wrong because manual acquisition through the device UI involves navigating menus and copying data manually, not using ADB commands. Option B is wrong because physical acquisition via JTAG requires hardware-level access to the device’s JTAG interface to dump raw flash memory, not a software command over USB. Option D is wrong because file system acquisition via `dd` creates a bit-for-bit image of a partition or block device, whereas `adb backup` only extracts logical files and does not capture deleted data or unallocated space.

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Option A is wrong because creating a mutex and writing a Run key are not techniques for privilege escalation; privilege escalation typically involves exploiting vulnerabilities (e.g., via token manipulation or kernel exploits) to gain higher access rights, not mutex or registry operations. Option B is wrong because mutex creation and Run key persistence are local system actions; communication with a command-and-control server would involve network connections (e.g., HTTP, DNS, or IRC traffic) and is not directly indicated by these artifacts. Option C is wrong because the mutex name 'Global\XPSS-1.0.0' is not a standard system mutex (system mutexes often use 'Global\' prefix with well-known names like 'Global\MSCTF.CtfMonitor') and the Run key is a well-known persistence location, not a hiding technique; hiding would involve rootkits, fileless techniques, or stealthy registry locations like HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\Explorer\Run.

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Option A is wrong because notifying employees to preserve documents is a standard and necessary step to implement a legal hold, ensuring awareness and compliance. Option B is wrong because suspending routine deletion of emails older than 30 days is a proper preservation action that stops the destruction of potentially relevant ESI. Option D is wrong because taking a forensic image of relevant servers is a best-practice preservation technique that captures a point-in-time snapshot of data without altering it, fully compliant with legal hold requirements.

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Option A is wrong because NetFlow is a flow-based accounting and monitoring technology that exports aggregated flow records (e.g., source/destination IP, ports, protocol) rather than capturing full packet payloads; it cannot provide the raw packet-level data needed for deep forensic analysis. Option C is wrong because ARP spoofing actively sends forged ARP replies to redirect traffic through the attacker's machine, which alters the traffic flow and can cause network disruptions or detection, violating the requirement to not alter the traffic flow. Option D is wrong because setting a NIC to promiscuous mode only allows the workstation to receive all frames on the collision domain of its connected switch port, but on a modern switched network, the switch will not forward traffic destined for other ports to the forensic workstation, so promiscuous mode alone cannot capture traffic from other hosts without additional techniques like ARP spoofing or a SPAN port.

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Option A is wrong because powering on a server that has been shut down can alter volatile data (e.g., memory contents, temporary files, system logs) and may trigger anti-forensic mechanisms, destroying evidence. Option B is wrong because copying files directly to an external USB drive modifies file metadata (e.g., last access timestamps) and does not capture deleted data or unallocated space, violating forensic best practices. Option C is wrong because running an antivirus scan on a live or powered-off system can modify files (e.g., quarantine, deletion, or repair) and alter the evidence, compromising its integrity.

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Option A is wrong because Google account tokens stored in AccountManager are often synced to Google's servers and may be recoverable from cloud backups or Google's authentication logs, even after a factory reset. Option C is wrong because system logs in /data/log/ are plaintext files that, although overwritten by the reset, may still be partially recoverable using file carving techniques if the blocks have not been overwritten. Option D is wrong because deleted text messages from SQLite files reside in the /data partition, and while the database is wiped, unallocated space may still contain remnants of the deleted records that can be recovered with forensic tools like Cellebrite or Oxygen Forensic Detective.

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Option A is wrong because software write blockers can be used with USB drives; they intercept write commands at the OS level regardless of the interface (SATA, USB, etc.), though some may require specific driver support. Option C is wrong because software write blockers do not inherently prevent hashing; hashing algorithms like SHA-256 are applied to the acquired image by forensic tools (e.g., FTK Imager, dd with sha256sum) independently of the write blocker. Option D is wrong because software write blockers are generally less expensive than hardware write blockers, often being free or low-cost tools (e.g., built-in OS features or open-source utilities), while hardware blockers involve dedicated electronic components.

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Option B is wrong because the best evidence rule does not mandate authentication by a witness; authentication is a separate requirement under FRE 901, which can be satisfied through testimony or circumstantial evidence like hash values. Option C is wrong because the rule does not require paper copies; in fact, paper copies of digital documents are often considered duplicates and may be admissible if they accurately reflect the original, but the rule prefers the original or a reliable duplicate, not exclusively paper. Option D is wrong because while metadata preservation is a best practice in forensics, the best evidence rule itself does not explicitly require metadata preservation in all copies; it focuses on the content of the document, not its metadata.

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Option A is wrong because dcfldd is designed for disk imaging, not memory acquisition; tools like LiME or fmem are used for live memory dumps. Option B is wrong because dcfldd does not natively support compression; compression must be done via piping to gzip or using other tools like ewfacquire. Option C is wrong because dcfldd does not create a write-blocked connection; write-blocking is a hardware or software layer (e.g., using a hardware write-blocker or the Linux kernel's read-only mount) that must be established before running the imaging command.

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Option A is wrong because Nmap is a network scanning tool used for host discovery and port enumeration, not for capturing live traffic from a SPAN port; it does not support packet capture or promiscuous mode for forensic traffic acquisition. Option C is wrong because Netcat is a simple networking utility for reading/writing data across network connections, lacking the packet capture, filtering, and timestamping capabilities needed for forensically sound traffic acquisition from a SPAN port. Option D is wrong because while Tcpdump can capture packets, it is a command-line tool that lacks the graphical analysis features and advanced file format support (e.g., pcapng) of Wireshark, making it less suitable for comprehensive forensic capture and review, though it can be used in a pinch.

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Option B is wrong because a graceful shutdown triggers OS cleanup processes that overwrite volatile data in RAM and may alter disk artifacts (e.g., pagefile, registry hives), violating forensic integrity. Option C is wrong because booting from a forensic live CD would overwrite portions of RAM and potentially modify the SSD (e.g., via temporary files or partition table changes), and using 'dd' without a write-blocker on a running system risks writes to the source drive. Option D is wrong because immediately unplugging the power cord loses all volatile data (RAM, network connections, process lists) that must be preserved per policy, and it may cause filesystem corruption on the SSD.

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Option A is wrong because unplugging the laptop immediately destroys volatile data (RAM contents, encryption keys, network state) and may cause file system corruption from an unclean shutdown. Option B is wrong because removing the hard drive while the system is running is physically dangerous and technically impossible without first powering off; moreover, capturing RAM from the drive is nonsensical—RAM is volatile memory, not stored on the hard drive. Option C is wrong because creating a full disk image over the network while the laptop is running modifies the system state (network traffic, open files, timestamps) and violates the principle of maintaining evidence integrity; network imaging should only be used when a write-blocked local acquisition is impossible, and even then volatile data must be captured first.

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Option A is wrong because the chain of custody is a procedural requirement for maintaining evidence integrity, not a statement of Locard's exchange principle. Option B is wrong because digital evidence can reside on local storage (e.g., hard drives, SSDs, RAM) as well as in the cloud; the principle applies regardless of storage location. Option C is wrong because multiple authorized personnel (e.g., first responders, investigators, analysts) may handle evidence under proper protocols, not exclusively the forensic examiner.

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Option A is wrong because Collection involves the actual acquisition of digital evidence (e.g., creating bit-for-bit forensic images using tools like dd or FTK Imager), not the initial scene documentation and labeling. Option C is wrong because Examination is the in-depth analysis of acquired data (e.g., file carving, registry analysis, timeline reconstruction), which occurs after evidence has been collected and preserved. Option D is wrong because Reporting is the final phase where findings are documented and presented, not the initial response activities.

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Option A is wrong because hashing is not performed by the conv parameter; hashing requires separate tools like sha256sum or md5sum, or using dd with piped output to a hash function. Option B is wrong because superuser privileges are obtained via sudo or running as root, not through conv parameters; conv controls data conversion, not permissions. Option D is wrong because compression is not a function of conv; compression requires piping dd output through gzip or using a separate tool like dc3dd with built-in compression.

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Option A is wrong because legal authority to seize evidence (e.g., a search warrant or subpoena) is a prerequisite for lawful collection, not the ongoing tracking of evidence after seizure. Option B is wrong because the order of forensic tool application (e.g., using FTK Imager before Autopsy) is a procedural workflow choice, not a documentation requirement for evidentiary integrity. Option C is wrong because physical security measures (e.g., locked safes, access logs) are part of evidence storage controls, but they do not constitute the chronological documentation of handling and transfer that defines chain of custody.

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