Exam PT0-002 topic 1 question 54 discussion

C. nmap -f --badsum 192.168.1.10 The option "nmap -f --badsum 192.168.1.10" is most likely to avoid detection by the client's IDS. The -f option allows nmap to send fragments of packets with bad checksums, which can cause some IDS to ignore the traffic. This will make the scan less detectable to the IDS, as it will not be able to identify the scan as malicious traffic. However, this option can cause the scan to be less accurate and efficient, and it should be used with caution.

This same page says -P0 will appear in logs. It's C. https://nmap.org/book/man-bypass-firewalls-ids.html If Nmap is run without the -P0 flag when performing third-party scanning, the source IP address of the attacker’s host performs ICMP and TCP pinging of the target hosts before starting to scan; this can appear in firewall and IDS audit logs of security-conscious organizations.

I changed my answer. The correct answer is: A. nmap -P0 -T0 -sS 192.168.1.10 Explanation: -P0 (or -Pn in newer versions): This option prevents nmap from pinging the target before scanning. Many IDS/IPS systems monitor ICMP echo requests (pings), and by skipping this step, the scan is less likely to be detected. -T0 (Paranoid Timing): This option slows down the scan significantly, making it less likely to trigger IDS alerts. It sends packets with long delays, minimizing the chance of detection. -sS (Stealth/SYN Scan): This is a half-open scan that only sends SYN packets without completing the TCP handshake. If the target responds with a SYN-ACK, the scanner does not complete the connection (by sending an ACK). Instead, it sends an RST, making it less likely to be logged by an IDS compared to a full connection scan.

C: because fragmented packets with the incorrect checksum (--badsum) are hard to detect. A Syn Scan (-sS) is able to be detected by IDS/IPS

The answer is A

A. nmap -P0 -T0 -sS 192.168.1.10 -P0: This option tells Nmap not to ping the host before scanning, which can help avoid detection as it doesn’t generate ICMP echo requests that might alert the IDS. -T0: This sets the timing template to the slowest option, which reduces the scan speed and can help to evade detection by not overwhelming the target's network or IDS. -sS: The SYN scan is stealthier than other scan types because it doesn't complete the TCP handshake, which makes it harder for IDS systems to detect. Other Options: C. nmap -f --badsum 192.168.1.10: This command uses fragmented packets and sends packets with bad checksums. It can bypass some basic filtering, but may still be flagged by more sophisticated IDS systems.

A. nmap -P0 -T0 -sS 192.168.1.10 -P0: This option disables host discovery, meaning Nmap won't send ICMP echo requests (ping) to determine if hosts are up. -T0: Sets the timing template to paranoid, which slows down the scan to reduce the likelihood of detection. -sS: Performs a SYN scan, which is stealthier than other scan types like a TCP connect scan (-sT).

A. B. -sA performs an ACK scan, which is used for mapping firewall rules but does not identify open ports. -sV attempts version detection, which sends additional probes that can be detected by IDS. --host-timeout 60 sets a host timeout of 60 seconds, which might not be slow enough to avoid detection. C. -f enables packet fragmentation, which can help avoid detection but might not be effective against all IDS. --badsum sends packets with incorrect checksums, which might be detected by IDS as abnormal traffic. D. -A enables aggressive scan options, including OS detection, version detection, script scanning, and traceroute. These aggressive options generate significant traffic and are likely to be detected by IDS. -n disables DNS resolution, which does not contribute significantly to stealth.

Cert master says that despite using T0, some IDS's can detect the handshake sequence and still catch the scan. Also, this would take a long time. Fragmenting and badsum are recommended in cert master for avoiding IDS detection.

The answer is A. I understand that C is a better choice in the real world, but -badsum is not covered in the official manual. The answers are reflecting questions and -badsum doesn't really. Setting -P0 -T0 and -sS is trying to explicetly avoid detection. A smart IDS will detect -badsum, maybe. But it's not a dice.

Between options A and B: A. nmap -P0 -T0 -sS 192.168.1.10 B. nmap -f --badsum 192.168.1.10 Option A is likely the more cautious approach for avoiding detection. Setting the timing template to the slowest timing (-T0) and skipping the ping scan (-P0) can reduce the aggressiveness of the scan. This slower approach might make the scan less conspicuous and decrease the likelihood of triggering alerts on the Intrusion Detection System (IDS). Option B, while utilizing fragmenting packets and sending packets with a bad checksum, may introduce a level of obscurity but might also trigger IDS alerts, as such techniques can be detected by sophisticated security systems.

When attempting to avoid detection by an IDS (Intrusion Detection System), a penetration tester may use techniques to make the scan less conspicuous. Among the given options, the scan that is MOST likely to avoid detection is: C. nmap -f --badsum 192.168.1.10 This command uses the --badsum option to generate packets with a bad checksum and the -f option to enable fragmenting packets. These techniques can sometimes be used to evade simple IDS signatures, as they might be interpreted as fragmented or corrupted traffic. However, it's important to note that the effectiveness of evasion techniques can vary, and sophisticated IDS may still be able to detect such scans.

A is the correct answer. If Nmap is run without the -P0 flag when performing third-party scanning, the source IP address of the attacker’s host performs ICMP and TCP pinging of the target hosts before starting to scan; this can appear in firewall and IDS audit logs of security-conscious organizations.

C. nmap -f --badsum 192.168.1.10, which uses fragmented packets and packets with bad checksums, would be the MOST likely to avoid detection by the client's IDS. Fragmenting packets can make it more challenging for IDS to reassemble and analyze the packets, and using bad checksums might allow the packets to evade certain detection rules.

This is another of those confusing ones, A might be correct yet C is also worth looking at, I will go with C here as the official nmap website has both -f and badsums under Firewall/IDS Evasion and Spoofing...https://nmap.org/book/man-bypass-firewalls-ids.html

Option A, "nmap -P0 -T0 -sS 192.168.1.10," may evade detection by some IDS systems, but it is less likely to be successful than option C. The "-P0" option disables host discovery using ICMP echo requests, which can prevent the target system from generating any logs related to the scan. However, some IDS systems may detect the SYN scan ("-sS") option used to perform the port scan. The "-T0" option sets a low timing template for the scan, but this alone may not be enough to avoid detection by some IDS systems. In addition, this option can also result in slower scans and longer wait times. Overall, while option A may provide some level of evasion from detection, option C, "nmap -f --badsum 192.168.1.10," is more likely to evade detection by using fragmentation and incorrect checksums to bypass some IDS systems.

C (nmap -f --badsum 192.168.1.10)