Security scanner for computers and networks.

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31
votes
3answers
72k views

How to find live hosts on my network?

I am trying to find the live hosts on my network using nmap. I am scanning the network in Ubuntu using the command sudo nmap -sP 192.168.2.1/24. However, i am unable to find the live hosts. I just get ...
15
votes
2answers
2k views

Is it possible to identify who's behind a nmap -D scan?

Nmap's -D option stands for decoy, which means that the attacker can simulate that the attack is coming from multiple IPs, including attacker's IP. From the point of view of the victim, is it ...
11
votes
4answers
2k views

Is my network being sniffed?

Is there any way to find out if someone who is connected to my network is sniffing packets? There is a way with nmap if his card is in promiscuous mode but what if it is passive?
9
votes
4answers
3k views

nmap showing unknown IPs on private network

I had a go at scanning my home network with nmap, doing a 192.168.0.0/16 netscan. To my surprise, the results shown multiple live devices not only on 192.168.1.x (where all our known devices are) but ...
8
votes
4answers
5k views

How to detect hosts running in virtual machines with nmap?

I have to determine if a given subnet has virtual hosts. Are there any ideas about what switches to use?
7
votes
2answers
357 views

How nmap guesses the operating system?

nmap has the capability to guess the operating system with the option -O. I was highly surprised that it can find the correct kernel or service pack. * How nmap guesses the operating system? * What ...
6
votes
3answers
9k views

How does “traceroute over TCP” work, what are the risks, and how can it be mitigated?

There is a utility called tcptraceroute, and this enhancement called intrace that is used just like a standard traceroute, but it works over TCP. How is the syn flag in TCP used to achieve ...
6
votes
2answers
3k views

Scanning my network with NMAP

Each computer is assigned one ip address on my network, and my ISP supplies one IP for my network. If I try to scan the ip supplied by my ISP what I got is the OS running on the router, running on the ...
6
votes
4answers
660 views

Trying to firewall ports 1863, 5190

I'm using Debian's arno-iptables-firewall and I've configured it to only allow access on the ports I need. But nmap shows ports 1863, 5190 open. What gives? How can I interrogate those ports further? ...
6
votes
2answers
1k views

How does nmap do a zombie and decoy scan?

We're learning nmap in my ethical hacking class. We got showed how we can use nmap to perform a zombie scan: nmap -PN -sI zombieIP targetIP and decoy scan: nmap -p 135 -D decoyIP targetIP I ...
5
votes
4answers
1k views

Persisting and comparing NMAP scans

Does anyone have any good recommendations on a good tool for persisting NMAP scans to database? It may be a tool for persisting or simply a java library for easy parsing of the nmap xml scan result ...
5
votes
2answers
1k views

How can I use nmap to distinguish between a normal linux machine and an android device?

According to this link: here, nmap 5.2 onwards is now supposed to detect android smartphones. I am using nmap 6.01 but it only identifies android devices as running a linux kernel.
5
votes
1answer
1k views

How to use NMap to portscan a SonicWall that is blocking all attemtps?

It seems that SonicWall is blocking attemtps to scan its ports. I know it has some ports open, like 443, because if I access using the browser I get a web site. But when I try to use NMap I can't see ...
5
votes
1answer
123 views

Where can I use the TCP FIN scan?

For a coursework i've got to run the various port scans, i'm having trouble with the FIN scan though, I can't seem to find a system where I can try it, everywhere I try it all ports either come back ...
4
votes
5answers
1k views

How to bypass Nmap blockage?

I rent a server, and my provider seems to be blocking nmap. Is there any other tools I could use to test my home network from the outside? Also, does blocking nmap on a network provide any security? ...
4
votes
3answers
388 views

Are there any example domains where I can run my nmap scans just to learn?

I want to learn nmap and its various options. Are there any example domains which purposefully have security holes to facilitate learning nmap?
4
votes
4answers
1k views

How can I scan open ports without being traced back

I would like to scan open ports of a server. But as far as I know, when I try to scan the open ports with something like nmap in shell they would be able to trace me. Is there a way to secure this ...
4
votes
2answers
674 views

Detect what is running on an open port?

I have a wireless camera in my network. Running nmap on the camera, I discovered that the port 1010 is open but I could not find what it is used for. I looked in the administration pannel and did not ...
4
votes
3answers
925 views

Sharing Nmap scan results in a web page

Is there a tool that allow the sharing of nmap scan results ? I know nmap can produce XML and I can easily convert them in HTML. I would like to know if there is a tool with more features. For ...
4
votes
1answer
398 views

Is it possible to detect host-machine of my virtual-machines?

So basically I need to know is there any way to find a connection (or relation) between packets sent by my VMs and my host machine. In my lab I have lots of workstations, each running a VirtualBox ...
4
votes
3answers
13k views

How to bypass tcpwrapped with nmap scan

I'd a scan task and I faced following result Host is up (0.032s latency). Scanned at 2012-10-25 16:06:38 AST for 856s PORT STATE SERVICE VERSION 1/tcp open tcpwrapped 3/tcp open ...
3
votes
2answers
360 views

Which ports are potential security risks for nmap?

I'm using nmap and I am having trouble finding which ports are dangerous and pose the greatest security risks. Which ports are potential security risks for nmap? I was thinking samba, telnet, vnc ...
3
votes
2answers
6k views

Could Nmap scan switches/routers

Nmap can scan and sometimes successfully detect the running OS in the remote host. However, can nmap scan routers and switches? Most of them use an embedded system.
3
votes
2answers
1k views

OS Fingerprinting for Android

Are traditional OS-fingerprinting techniques effective in identifying Android smartphones (OS version) on a network. From my research I found most Android network mappers can be only run from Android ...
3
votes
1answer
110 views

Use nmap correctly

I currently have a VPS in a data center, I asked the admin to open a port to install a ftp server. It opened port 3345, at first I tought the port is not forwarded correctly, because I ran nmap as ...
3
votes
3answers
5k views

Why does an nmap -sT scan show ports filtered but -sS shows ports closed

What are possible reasons why an nmap -sT scan would show "ports filtered" but an identical nmap -sS scan shows "ports closed"? I understand that -sT is a full TCP Connect, which is easier to detect ...
3
votes
1answer
2k views

How can I see traceroute details in NMAP?

I'm using NMAP for Network scan ; The output does not contain the full traceroute details. Can I view all intermediate routers/hosts using the NMAP GUI? A simple VPN connection IP traceroute... ...
3
votes
1answer
3k views

Nmap scan produces all “unknown”

I scanned both localhost, and the IP address of the LAN adapter, and this is the produced output. Starting Nmap 5.51 ( http://nmap.org ) at 2012-10-12 18:06 Eastern Daylight Time Skipping SYN Stealth ...
3
votes
2answers
231 views

are there any services to test nmap

While playing with nmap, I have started to wonder: are there any ip addresses which were specifically made to learn how to use nmap. (As far as I understood I can not just scan any ip address, ...
3
votes
2answers
354 views

Determing live hosts past a restrictive firewall with nmap

Sometimes when I am doing an external security assesment, I run into hosts that have the following restrictions/configuration: All ICMP traffic is blocked An IDS or some device returns all ports as ...
3
votes
2answers
964 views

Why do multiple IP Addresses in my local network point to the same computer?

I'm new to linux and nmap, and I am attempting to do a scan of my local network. Using nmap I find that there are 4 hosts on my network (10.0.2.2, 10.0.2.3, 10.0.2.4, 10.0.2.15). I am using VirtualBox ...
2
votes
5answers
644 views

OS fingerprinting: can I rely on the results?

Using nmap -O www.example.com I get: Running (JUST GUESSING): Microsoft Windows 7|2008 (90%) So I can say the target site is running Windows. Using xprobe2 -v www.example.com, I'm just astonished ...
2
votes
5answers
2k views

Nmap reporting almost every port as open

I have noticed during some assesments when doing a TCP port scan, Nmap will report almost every port as open for a machine. Using for example nmap -sS -PN -T4 target -p0-65535, over 20,000 ports will ...
2
votes
1answer
118 views

nmap: why is it “silly” to combine OS finding option (-O) with bounce scan (-b)

If you run an Nmap FTP bounce scan with nmap -O -b, nmap will do the scan, but it says that the scan "seems silly" before it starts. Why would the scan be silly? It actually appears to report a ton ...
2
votes
2answers
3k views

NMAP DNS Service Detection

I was looking out how NMAP identifies DNS services. After determining that port 53 is open it issues a standard query TXT version.bind to find out if BIND is running on the domain port. Then, I saw ...
2
votes
2answers
553 views

How to block network scans with pfsense?

I am using pfsense as firewall, and I would like to know how I can stop network scans from enumerating open services and ports. Thanks
2
votes
1answer
56 views

Optimal flags to specify when using nmap to guess the OS on remote devices?

Optimal flags to specify when using nmap to guess the OS on remote devices? I'm currently using the following: nmap --privileged -sS -sU -sY -sZ -O --osscan-guess -F -r 192.168.200.223 This seems ...
2
votes
1answer
595 views

Why are some ports reported as closed by nmap?

I was scanning a machine from inside the same LAN which is running and up to date Windows XP Home Edition which I suspect may be running some malware. The target machine has an up to date antivirus ...
2
votes
2answers
90 views

Nmap scanning computers behind a wireless modem [closed]

Let's suppose that I have a router and three computers connected to Internet through that router. When I tried to get the external IP address for each computer, I got the same address. I think this ...
2
votes
1answer
39 views

Is there any difference for OS fingerprint technique used in Nmap inside -A and -O?

Is there any difference between the technique or algorithm used from Nmap to guess the OS between the option -A and -O? If not, why -O option requires root privileges but -A that it is doing at least ...
2
votes
1answer
76 views

Does nmap limit probes when using time limiting on decoy scans?

If I set a rate limit (e.g. -T1) on an nmap scan that uses decoys, does the rate limit apply to all probes, or just each individual source? I checked the documentation, but can't see anything ...
2
votes
1answer
213 views

Scan All private subnets with NMAP [closed]

I have a managed switch on my network but I don't remember the subnet. How can I scan all the private network without changing my ip address : 10.0.0.0/8, 172.16.0.0/12, 192.168.0.0/16 Thanks for ...
2
votes
1answer
3k views

Scan multicast IP range on specific port using nmap

I'd like to scan a multicast IP range on a specific port using nmap. When I try to simply do a nmap -p 10000 239.35.0.0/16, it just responds with an error stating Strange error from connect ...
2
votes
1answer
583 views

What are the best Nmap Scripting Engine (NSE) service discovery scripts? [closed]

Using nmap -sV can be quite verbose can -sU can take a very long time especially with -p 0-65535. To narrow your results and enumerate interesting services the wealth of NSE scripts can be very ...
1
vote
3answers
877 views

How to find the OS of the target machine

I am new to this field. Currently I am using Linux OS and my question is how can I find the OS of another machine to which I do not have a direct access. I am interested in any possibilities which ...
1
vote
2answers
2k views

nmap no ping returns host is active and all ports are filtered

I am trying to determine if hosts are up. For hosts where a ping fails, I run a nmap (6.40) Regular and/or Quick scan. For a subset of my hosts, the nmap response is "Host seems down". As a follow up ...
1
vote
4answers
2k views

How to make nmap list an unfiltered port?

I have a host that is NAT'ed and I have opened a single port in my router so the host is reachable by the external world. I tested if it was reachable by running a service and connecting to it ...
1
vote
1answer
1k views

How do I use nmap to scan a range of IPv6 addresses? [closed]

I need to scan a range of IPv6 addresses with Nmap, but I'm not sure how to do this. When scanning for an IPv4 range, I would usually do this: nmap -sP 192.168.*.* or nmap -sP 192.168.1.* but if ...
1
vote
2answers
1k views

Found Unusual Services running on my VPS

I am running a Debian VPS and i did a port scan and found these services 135/tcp filtered msrpc 139/tcp filtered netbios-ssn 445/tcp filtered microsoft-ds 593/tcp filtered http-rpc-epmap 1720/tcp ...
1
vote
3answers
254 views

What exactly does one get from a Nmap Scan?

I know nmap is a port scanner and its output shows all the open ports, the services running on those ports, the underlying OS and technology, etc. What should one take from this result in easiest ...