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312-50V10 · Question #643

Joseph was the Web site administrator for the Mason Insurance in New York, who's main Web the Web site. One night, Joseph received an urgent phone call from his friend, Smith. According to Smith, the

The correct answer is C. DNS poisoning. When a website appears defaced to external visitors but intact to internal users, the attack is consistent with DNS cache poisoning targeting external resolvers.

Sniffing

Question

Joseph was the Web site administrator for the Mason Insurance in New York, who's main Web the Web site. One night, Joseph received an urgent phone call from his friend, Smith. According to Smith, the main Mason Insurance web site had been vandalized! All of its normal content was removed and replaced with an attacker's message ''Hacker Message: You are dead! Freaks! From his office, which was directly connected to Mason Insurance's internal network, Joseph surfed to the Web site using his laptop. In his browser, the Web site looked completely intact. No changes were apparent. Joseph called a friend of his at his home to help troubleshoot the problem. The Web site appeared defaced when his friend visited using his DSL connection. So, while Smith and his friend could see the defaced page, Joseph saw the intact Mason Insurance web site. To help make sense of this problem, Joseph decided to access the Web site using his dial-up ISP. He disconnected his laptop from the corporate internal network and used his modem to dial up the same ISP used by Smith. After his modem connected, he quickly typed After seeing the defaced Web site, he disconnected his dial-up line, reconnected to the internal network, and used Secure Shell (SSH) to log in directly to the Web server. He ran Tripwire against the entire Web site, and determined that every system file and all the Web content on the server were intact. How did the attacker accomplish this hack?

Options

  • AARP spoofing
  • BSQL injection
  • CDNS poisoning
  • DRouting table injection

How the community answered

(28 responses)
  • A
    7% (2)
  • B
    14% (4)
  • C
    75% (21)
  • D
    4% (1)

Why each option

When a website appears defaced to external visitors but intact to internal users, the attack is consistent with DNS cache poisoning targeting external resolvers.

AARP spoofing

ARP spoofing operates at Layer 2 within a local network segment and cannot selectively redirect only external users while leaving internal users unaffected.

BSQL injection

SQL injection modifies the actual database content on the web server, which would make the defacement visible to all visitors regardless of network location.

CDNS poisoningCorrect

DNS poisoning corrupts the cache of external DNS resolvers so that public users resolve the domain to an attacker-controlled server hosting the defaced content. Joseph's internal network uses the company's authoritative or internal DNS, which remained uncorrupted, explaining why he saw the legitimate site while external users on DSL and other connections saw the defaced version.

DRouting table injection

Routing table injection manipulates IP routing paths at a network infrastructure level and would not produce the selective internal-versus-external visibility discrepancy described.

Concept tested: DNS cache poisoning attack identification

Source: https://www.cisa.gov/news-events/alerts/2019/01/16/dns-infrastructure-tampering

Topics

#DNS poisoning#cache poisoning#DNS spoofing#web defacement

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