Posts
Wednesday, March 27, 2019
How to Conduct Pentesting for any organisation (Complete Tutorial)
Pentesting means finding vulnerabilities by using various techniques and methods .
Organisations hire consultants who have team of complete auditors who perfrom the pentesting .
Auditors are those who know how to find vulnerabilities and perform exploits as well to check the securities issues .
Auditors perform the task depending upon the agreement signed between the organisation and the auditors .
Based on the agreement , Pentesting will be performed. Just like we have different type of hackings like ... black ,white and grey box .. similarly auditors perform pentesting based on the the rights provided to them.
Types of hacking
External pentesting
This type of hacking is done from the Internet against the client’s public network infrastructure; that is, on those computers in the organization that are exposed to the Internet because they provide a public service. Example of public hosts: router, firewall, web server, mail server, name server, etc.
Internal pentesting
As the name suggests, this type of hacking is executed from the customer’s internal network.
Black box hacking
This mode is applicable to external testing only. It is called so because the client only gives the name of the company to the consultant, so the auditor starts with no information.
Gray box hacking
This method is often refer to internal pentestings. Nevertheless, some auditors also called gray-box-hacking an external test in which the client provides limited information on public computers to be audited.
White box hacking
White-box hacking is also called transparent hacking. This method applies only to internal pentestings and is called this way because the client gives complete information to the auditor about its networks and systems.
Phases of hacking
Both the auditor and the cracker follow a logical sequence of steps when conducting a hacking. These grouped steps are called phases.
There is a general consensus among the entities and information security
professionals that these phases are 5 in the following order:
1-> Reconnaissance 2-> Scanning 3-> Gaining Access 4-> Maintaining Access 5-> Erasing Clues
Usually these phases are represented as a cycle that is commonly called “the circle of hacking” with the aim of emphasizing that the cracker can continue the process over and over again.
Though, information security auditors who perform ethical hacking services present a slight variation in the implementation phases like this:
Monday, March 18, 2019
Firewall, IDS, and IPS
The three devices commonly used to provide security are the firewall, the IDS, and the IPS.
Firewall
A firewall is a network security system that actively monitors and regulates the inbound and outbound network traffic based on a predefined security ruleset. A firewall typically acts a barrier between a trusted, secure internal network and an outside network, such as the Internet, which may not be secured enough. A firewall helps screen out malicious users, viruses, and worms that try to access your network from the Internet.
Some firewalls are simply software that runs on your computer, while other firewalls are sets of complete hardware devices and appliances. Firewalls can operate on individual hosts but are widely implemented on the network level. Firewalls are often used to create a Demilitarized Zone (DMZ), a physical or logical subsection of a network that separates the internal private LAN from the external untrusted network like the Internet. The resources that need to be accessed externally over the Internet, such as a web server hosting a website, are kept in the DMZ. The remaining resources, like the database server and backup servers are all kept in an internal private LAN and are not directly accessible over the Internet. Because the resources in a DMZ are directly accessible to the public, they need to be hardened for security. Firewalls also offer a feature known as stateful inspection , which monitors and keeps track of all the network connections and ensures that all inbound packets are the result of an outbound request. This feature was primarily designed to prevent harmful packets from entering the network and also defend against common information-gathering techniques like port scanning.
Intrusion Detection System
Unlike a typical firewall, which functions on predefined rules, an intrusion detection system is more intelligent in the way it detects various attacks. While a firewall may just check and restrict access to a particular system (based on IP address and port), the IDS would go an extra mile to check whether the traffic contains any malicious code, which might lead to an attack. Just as an anti-virus program has a signature database of known viruses, an IDS has a signature database for known and common attacks. It checks all packets traversing the network and tries to match them against its signature database. If a match is found, it raises an alert about the attack so that the network/system administrator can take appropriate steps to prevent it.
Intrusion Prevention System
An intrusion prevention system does all the jobs that an IDS does, but it also stops the attack (by dropping packets) whenever it encounters malicious traffic in network packets. This ensures an automated response to an attack and reduces manual intervention.
Do you know where the passwords are stored in linux?
Two important files in the Linux system are responsible for storing user credentials:
/etc/passwd
Is a text file that stores all the account information (except the password) required for user login.
The following sample entry from an /etc/passwd file will help clarify its components:
1. User Name: This is the username used to log in.
2. Password: The X character implies that encrypted password for this user is stored in the /etc/shadow file.
3. User ID (UID): Each user on the system has a unique ID. UID 0 (zero) is reserved for the root user.
4. Group ID (GID): This is the group ID of the group to which the user belongs.
5. User ID Info: This comment field can store additional information about the user, including email, telephone number, and so on.
6. Home Directory: This is the default directory that will be available for the user after login. All the user-specific documents and settings are stored in the respective home directory.
7. Command/Shell Path: This is the path to the command prompt, or shell .
/etc/shadow
Is a text file that stores actual passwords in hashed format. It also stores parameters related to the password policy that has been applied for the user. Following is an example entry from the /etc/shadow file:
1. Username: This is the username to which the password belongs.
2. Password: This is the password stored in hashed format.
3. Last password change: This field indicates the number of days since the last password change.
4. Minimum Age: This denotes the number of days remaining before the user can change his or her password.
5. Maximum Age: This denotes the maximum number of days after which the user must change his or her password.
6. Expiry Warning: This denotes the number of days before which the user must be warned about the password expiring.
7. Inactive: This is the duration in days after password expiry that the account will be disabled.
Wednesday, March 13, 2019
Defensive measures for Protecting Exploitation in Organisational Environment
Create a security policy that includes a section about password guidelines (key length, use of special characters, periodical expiration of keys, account blocking policy, etc.)
Enable auditing services at the operating system level in end-user devices, servers and communications equipment and use log correlation software to perform event monitoring.
Restrict access to the Administrator and root account so that it cannot perform logon through the network, but only physically in the computer console.
Use port security and admission control (NAC) on networking devices so that only authorized users can connect to the network.
Replace insecure protocols that send information in plain text as HTTP, SMTP, TELNET, FTP, with their secure counterparts which use digital certificates and encryption for transmission: HTTPS, SMTP, SSL, SSH, SFTP, etc.
Set the switches to detect the sending of free and unauthorized ARP and other known attacks and react to port violation taking appropriate actions and reporting the event.
Implement secure authentication protocols in wireless equipment and isolate wireless segments from other internal subnets using intelligent next generation firewalls68.
Configure intelligent next generation firewalls and other network devices to block attacks.
Use network and security management software for threat detection, vulnerability assessment and automatic response to events.
Design and implement an Information Security Policy based on the ISO 27000 standard.
mplement awareness campaigns about good practices on information security for the end-users.
Train staff from the IT and related departments about information security and specialized topics such as ethical hacking, computer forensics and defense mechanisms.
Define profiles for IT personnel and establish which international certifications on information security your functionaries must obtain according to their position.
Tuesday, March 12, 2019
Preventive Measures to Stop Enumeration
Multiple protocols are susceptible of enumeration, we should ask our
client which ones are really needed in the network. The obvious preventive measure is to disable those insecure protocols that are not required in the network.
However, this is not always feasible, especially if there are legacy applications in the organization that depends on insecure protocols to operate and for which there is no migration scheduled in the short term.
Some defensive measures that you can suggest to your client are:
Configure filter rules on the perimeter firewall(s) to prevent that protocols susceptible to enumeration that do not perform a public function be exposed to Internet (e.g. Netbios).
Implement a migration plan to update the version of legacy operating systems and applications periodically based on cost/benefit. In companies where the number of workstations is large, you might consider a project to replace the desktops by thin clients by using virtualization. License costs are usually lower in virtual environments.
Similarly, in environments with many servers, a consolidation process could not only provide savings in energy consumption, but also on maintenance costs of hardware/software and administration.
If you have a predominantly Windows network, you can deploy Active Directory policies to prevent the establishment of invalid logon sessions and disable the login through the network for the built-in Administrator account. However, care must be taken with legacy programs that could use null sessions.
Monday, March 11, 2019
Defensive measures for Less exposure of Vulnerabilities during scanning
Although the only 100% secure network is the one that is disconnected, we may take defensive measures that help us minimize security risks in our infrastructure during the scan.
Here are some precautions that we can take:
To start, you cannot scan an application that is not installed. This means that before putting a target on production we should do a “hardening” of the operating system, applications and services.
Hardening means “minimize”. Therefore, for a server to perform a specific function there is no point to enable unnecessary services, neither should be installed applications that do not serve the intended purpose. For example,
if the target would be only a Web server (HTTP/HTTPS), then why the service IRC (chat) have to be enabled?
By preventing unnecessary applications remaining active on the equipment, we prevent that potential vulnerabilities become a point for future exploitation.
Enable automatic update of the operating system patches that fix security issues so they are installed in a timely manner.
Keep up support contracts with the hardware/software providers, to reach them in case of an eventuality, for example; a zero-day vulnerability (for which there is no patch yet).
Redesigning the network to include security measures such as segmentation to separate security zones by intelligent next generation firewalls.
Set rules in firewalls to filter unauthorized access from the Internet and internal subnets ports.
Install intrusion prevention systems (IPS) that can work with firewalls and other network devices to detect threats (such as ping sweeps, mass scanning, etc.) and block them immediately.
Perform periodic analysis of vulnerabilities to detect any possible threats to the security of our network and take appropriate corrective actions.
Sunday, March 10, 2019
How to conduct Professional Pentesting|Part-2 | Reconnaissance or footprinting
Reconnaissance is the first phase in the implementation of a hacking. The aim of this phase is to discover as much relevant information as we can from the client’s organization or victim.
Now, depending on whether the interaction with the target is direct or indirect, the reconnaissance can be active or passive.
Passive reconnaissance
We say the reconnaissance is passive when we have no direct interaction with the client or victim. For example, we use a search engine like Google and inquire the name of the audited company, in the results we get the name of the client’s website and discover that the web server name is www.enterprisex.com, then we do a DNS search and get that the IP address of that server is 200.20.2.2
Active Reconnaissance
In this type of reconnaissance there is a direct interaction with the target or victim. Examples of active reconnaissance:
Ping sweeps to determine the active public computers within a range of IP’s. Connecting to a service port in order to gather a banner and try to determine the software version.
Using social engineering to obtain confidential information.
Reconnaissance tools
The hacker’s platform it’s up to you, but if you ask my opinion I prefer to use Kali Linux.
Footprinting with Google
Google is undoubtedly the most widely used due to its classification technology web pages (Page Rank), which allows us to search quickly and accurately. For our reconnaissance example with Google we will begin with the most simple: searching for the company’s name.
In this example we’ll use as victim the Project Scanme by Nmap8. Scanme is a free site maintained by Fyodor, the creator of NMAP port scanner.
Google operators:
(plus symbol): is used to include words that because they are very common are not included on Google search results. For example, say that you want to look for company The X, given that the article “the” is very common, it is usually excluded from the search. If we want this word to be included, then we write our search text like this: Company +The X
(minus symbol): is used to exclude a term from results that otherwise could include it. For example, if we are looking for banking institutions, we could write: banks -furniture
”” (double quotes): if we need to find a text literally, we framed it in double quotes. Example: “Company X”
~ (tilde): placing this prefix to a word will include synonyms thereof. For example, search by ~company X will also include results for organization X
OR: This allows you to include results that meet one or both criteria. For example, “Company X General Manager” OR “Company X System Manager”
site: allow to limit searches to a particular Internet site. Example: General Manager site:companyX.com
link: list of pages that contain links to the url. For example, searching for link:companyX.com gets pages that contain links to company X website.
filetype: or ext: allows you to search by file types. Example: Payment roles + ext:pdf site:empresax.com
allintext: get pages that contain the search words within the text or body thereof. Example: allintext: Company X
inurl: shows results that contain the search words in the web address (URL). Example: inurl: Company X
Of course there are more operators that can be used with Google, but I think these are the most useful.
Returning to our reconnaissance example, we found among the results some pages about the NMAP organization. The one that catches our attention is scanme.nmap.org, this brings us to our next tool: DNS name resolution.
Determining names with nslookup
Now that we know the main site of our client, we can make a DNS query obtain its IP address. In a real case it is possibly to find more than one customer site referenced by Google and therefore we’ll get several IP addresses. Actually, the idea behind getting this first translation is to estimate the range of IP’s that we will need to scan in order to identify additional hosts that could belong to the client.
Assuming that our target is using IPv4 addresses, we could test the whole range of hosts inside the subnet.
The latter is impractical if you try to address Class A or B, since the scanning process could last longer. To determine the range more accurately, we can use other means as looking in Who-Is directories or performing socia engineering attacks. In this example we will made a name query using the nslookup command
DNS resolution with nslookup on Windows
Note: During an audit of any kind it is important to be organized and take notes of our findings. This will allow us to tie up loose ends while revealing more information as we go.
Returning to the nslookup command, we still can learn more from our target. We will use some useful options:
set type = [NS | MX | ALL] to set the query type, NS name service, MX mail service (mail exchanger) and ALL to show everything.
ls [-a | -d] domain enables you to list the addresses for the specified domain (for which the DNS server for that domain must have this option enabled) -a canonical names and aliases, -d all records in the DNS zone.
Maltego
Maltego is a tool that allows collecting data from an organization easily, through the use of graphic objects and contextual menus that let you apply “transformations”
You can also collect all the artifacts in the form of pdf reports ....like
Visual IP Trace route
During the execution of an external black box hacking is useful to know the
geographical location of a particular target. Imagine for example that we have obtained the names of the mail server and web server of our client and want to know if these services are hosted on the public network managed by the company itself or if instead, they are located in an external hosting as Yahoo Small Business , Gator, or similar. Why do we want to know this? Very simple, if the target servers happen to be held on an external hosting, in the event we managed to break into such equipment, we would actually be hacking the hosting provider, not our client, in which case we could face a possible lawsuit. Because of this, it is strongly recommended to perform a trace route to discover the geographical location of a target host. That way we would be able to decide “to hack or not to hack”.
There are several applications on the market that perform visual traceroute, to name a few: Visual IP Trace, Visual Route. Some of them are free or have paid versions with additional features such as the likelihood of generating reports.
E-mail tracking tools
It is possible that during the execution of an external hacking we come across a case in which our client has outsourced DNS, E-mail and Web services, and everything we do only lead us to the hosting provider.
This implies that at least the ISP has assigned to our client one public IP for
outbound Internet, so there has to be a router or a firewall doing NAT so that internal users can navigate – I’m assuming the client uses IPv4. If this is the case, then getting this public IP address is now our target, let’s see how we can get this through the analysis of an email.
Raised this new goal now we would make our customer send us an email, and only then we will be able to analyze data from the email header in order to determine the source IP address. This is pretty simple since we have been hired by them to run an ethical hacking, so we could send e-mail pretending to show them how the audit is progressing and wait for the response. For this analysis we can use any email tracking tool or we can manually review the email header; but the use of automated tools has the advantage of obtaining a report. It should be mentioned that the email analysis tools not only help to identify an email source IP address, but also show whether the sender is indeed who he says he is, we can use these applications to determine if we’re dealing with a false email or a phishing email.
Subscribe to:
Posts (Atom)
