- All public records, accessing is not illegal.
- Query and response protocol (port 43)
- Used for retrieving information about assigned Internet resources
- To get WHOIS information you can
- Use different websites such as whois.net
- Use command-line:
whois cloudarchitecture.io
- Two models
- Thick WHOIS: information from all registrars for the specified set of data.
- Thin WHOIS: limited information about the specified set of data.
- Domain details
- 📝 Domain owner details
- Includes contact information of the owner
- Can be hidden by a WHOIS guard
- A proxy between the owner of the domain and who's accessing
- Emails are usually still redirected to the owner.
- 💡 Allows for e-mail phishing to learn who the actual owner is.
- Domain server
- Who it's registered with e.g. NameCheap.com, Gandi.net
- 💡 Site owner might have account in the server, and you can test passwords there.
- Net range
- Domain expiration
- 💡 If auto-renewal fails, someone can transfer a domain to another address for malicious behaviors or just to sell it back to you.
- Creation and last update dates
- WHOIS databases are maintained by the Regional Internet Registries (RIRs) such as:
- ARIN: American Registry for Internet Numbers
- AFRINIC: African Network Information Center
- APNIC: Asia Pacific Network Information Center
- RIPE: Réseaux IP Européens Network Coordination Centre
- LACNIC: Latin American and Caribbean Network Information Center
- 🤗 Every ISP, hosting company etc. must be member of one of the registries to get IP addresses.
- Helps find location information about a target
- Includes country, city, postal code, ISP, and so on
- Country is mostly accurate but city, coordinates are not but approximated
- Helps with social engineering attacks
- E.g. GeoIpTool.com
- Collecting information about DNS zone data.
- e.g. server types and their locations
- Includes information about key hosts in the network
- 📝 E.g.
host -t a cloudarchitecture.com
-
t
stands for type of domain recorda
gives A type of domain records. -
Returns something likes this:
cloudarchitecture.io has address 13.33.17.159 cloudarchitecture.io has address 13.33.17.136
-
A records returns multiple IP addresses to increase speed and availability e.g. when hosting same content in multiple continents.
-
- See also DNS enumeration
- Use one of IP addresses that's listed as an A
host 13.33.17.159
- Returns
159.17.33.13.in-addr.arpa domain name pointer server-13-33-17-159.arn53.r.cloudfront.net.
- Returns
- Multiple IP addresses can be tied to same domain
- multiple domain addresses that are tied to the same IP
- Can be retrieved with
-t mx
- Exposes which e-mail service they use
- Have a preference number to tell the SMTP client to try (and retry) each of the relevant addresses in the list in order, until a delivery attempt succeeds
- The smallest preference number has the highest priority
- 💡 Once a hacker know who the e-mail provider is, he/she can create fake-mails using the provider to test e.g.
- What kind of content is allowed
- If a file be modified so it appears as PDF but make it executable
- When an e-mail is labeled as spam / malicious