HackTheBox-Challenges Easy Phish Writeup
                
            
             
        
            
                
                
                    
                        kazma
                        
                            Security Researcher
                        
                    
                    
                 
             
        
        
        
            Description
Customers of secure-startup.com have been recieving some very convincing phishing emails, can you figure out why?
直接放上解法:
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 | ╰─ dig TXT secure-startup.com _dmarc.secure-startup.com                                       ─╯
 
 ; <<>> DiG 9.10.6 <<>> TXT secure-startup.com _dmarc.secure-startup.com
 ;; global options: +cmd
 ;; Got answer:
 ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 27205
 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
 
 ;; OPT PSEUDOSECTION:
 ; EDNS: version: 0, flags:; udp: 1232
 ;; QUESTION SECTION:
 ;secure-startup.com.		IN	TXT
 
 ;; ANSWER SECTION:
 secure-startup.com.	1800	IN	TXT	"v=spf1 a mx ?all - HTB{RIP_SPF_Always_2nd"
 
 ;; Query time: 379 msec
 ;; SERVER: 1.1.1.1#53(1.1.1.1)
 ;; WHEN: Mon Aug 26 16:33:09 CST 2024
 ;; MSG SIZE  rcvd: 101
 
 ;; Got answer:
 ;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 49225
 ;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1
 
 ;; OPT PSEUDOSECTION:
 ; EDNS: version: 0, flags:; udp: 1232
 ;; QUESTION SECTION:
 ;_dmarc.secure-startup.com.	IN	TXT
 
 ;; ANSWER SECTION:
 _dmarc.secure-startup.com. 1800	IN	TXT	"v=DMARC1;p=none;_F1ddl3_2_DMARC}"
 
 ;; Query time: 382 msec
 ;; SERVER: 1.1.1.1#53(1.1.1.1)
 ;; WHEN: Mon Aug 26 16:33:09 CST 2024
 ;; MSG SIZE  rcvd: 99
 
 | 
因為題目提到這個 domain 存在一些釣魚郵件的問題,合理懷疑是 DMARC 相關的設定可能有問題,因此我們可以去 dig 他的 DNS 紀錄。
補充介紹 DMARC:
DMARC(Domain-based Message Authentication, Reporting, and Conformance,網域型訊息驗證、報告與遵循)是一種基於網域的電子郵件驗證系統,旨在提高郵件傳送者和接收者對電子郵件真實性的信心。其核心目的是幫助減少垃圾郵件和釣魚攻擊,特別是那些偽裝成合法網域的郵件。
Pwned !!!!
