eBanking Phishing Delivered Through IPv4-Mapped IPv6 Address, (Fri, Jun 19th)
A phishing campaign targets a major Belgian bank using a URL that employs an IPv4-mapped IPv6 address notation to evade simple security controls. The attacker uses a literal IPv6 address format containing an embedded IPv4 address in hexadecimal, bypassing regular expression-based domain and IP detection. The malicious URL redirects to a phishing kit hosted on a separate domain. This technique leverages RFC 4291 IPv4-mapped IPv6 addresses to obscure the true destination IP address.
AI Analysis
Technical Summary
This phishing threat involves a classic phishing email targeting a major Belgian bank. The notable technical aspect is the use of an IPv4-mapped IPv6 address in the URL, formatted as a literal IPv6 address (e.g., hxxp://[::ffff:5511:74be]/...), which corresponds to an IPv4 address encoded in hexadecimal. This approach is designed to bypass simple security controls that rely on extracting domain names or IPv4 addresses using regular expressions. The URL does not have a DNS record and redirects to another domain hosting the actual phishing kit. The IPv4-mapped IPv6 address technique is defined in RFC 4291 and is used here to evade detection.
Potential Impact
The phishing attack aims to deceive recipients into visiting a malicious URL that is obfuscated using IPv4-mapped IPv6 notation, potentially bypassing some security filters. Successful phishing could lead to credential theft or other typical phishing impacts. There is no indication of exploitation in the wild beyond detection, and the phishing technique itself is not a software vulnerability but a social engineering threat leveraging URL obfuscation.
Mitigation Recommendations
No official patch or fix applies as this is a phishing technique rather than a software vulnerability. Security teams should update detection rules and URL parsing logic to recognize IPv4-mapped IPv6 addresses and decode them to their IPv4 equivalents. Awareness training for users about phishing risks remains important. Since the phishing URL uses no DNS record and relies on IP notation, network defenses should consider inspecting literal IP addresses in URLs. Monitor for similar obfuscation techniques in phishing campaigns.
eBanking Phishing Delivered Through IPv4-Mapped IPv6 Address, (Fri, Jun 19th)
Description
A phishing campaign targets a major Belgian bank using a URL that employs an IPv4-mapped IPv6 address notation to evade simple security controls. The attacker uses a literal IPv6 address format containing an embedded IPv4 address in hexadecimal, bypassing regular expression-based domain and IP detection. The malicious URL redirects to a phishing kit hosted on a separate domain. This technique leverages RFC 4291 IPv4-mapped IPv6 addresses to obscure the true destination IP address.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This phishing threat involves a classic phishing email targeting a major Belgian bank. The notable technical aspect is the use of an IPv4-mapped IPv6 address in the URL, formatted as a literal IPv6 address (e.g., hxxp://[::ffff:5511:74be]/...), which corresponds to an IPv4 address encoded in hexadecimal. This approach is designed to bypass simple security controls that rely on extracting domain names or IPv4 addresses using regular expressions. The URL does not have a DNS record and redirects to another domain hosting the actual phishing kit. The IPv4-mapped IPv6 address technique is defined in RFC 4291 and is used here to evade detection.
Potential Impact
The phishing attack aims to deceive recipients into visiting a malicious URL that is obfuscated using IPv4-mapped IPv6 notation, potentially bypassing some security filters. Successful phishing could lead to credential theft or other typical phishing impacts. There is no indication of exploitation in the wild beyond detection, and the phishing technique itself is not a software vulnerability but a social engineering threat leveraging URL obfuscation.
Mitigation Recommendations
No official patch or fix applies as this is a phishing technique rather than a software vulnerability. Security teams should update detection rules and URL parsing logic to recognize IPv4-mapped IPv6 addresses and decode them to their IPv4 equivalents. Awareness training for users about phishing risks remains important. Since the phishing URL uses no DNS record and relies on IP notation, network defenses should consider inspecting literal IP addresses in URLs. Monitor for similar obfuscation techniques in phishing campaigns.
Technical Details
- Article Source
- {"url":"https://isc.sans.edu/diary/rss/33090","fetched":true,"fetchedAt":"2026-06-19T08:50:06.234Z","wordCount":358}
Threat ID: 6a3502bef198dc38c1d4b1dd
Added to database: 6/19/2026, 8:50:06 AM
Last enriched: 6/19/2026, 8:50:10 AM
Last updated: 6/19/2026, 9:16:41 PM
Views: 13
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