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Phishing alert: beware of the 'post quantum' snail mail scam

Phishing Alert | Snail Mail Scam Targets Coldcard Holders ๐Ÿšจ๐Ÿ—ž๏ธ

By

Michael Chen

Jun 24, 2026, 10:31 PM

Updated

Jun 24, 2026, 10:59 PM

2 minutes reading time

A close-up of a physical letter featuring a suspicious QR code, warning against a phishing scam targeting Coldcard owners.

A rising tide of concern envelops Coldcard wallet users due to a phishing campaign leveraging physical letters. As the deadline looms on June 30, recipients are urged to safeguard themselves against attempts to harvest sensitive information through QR codes that seem legitimate at first glance.

Breakdown of the Scam

Individuals have reported receiving alarming letters about supposed quantum threats to their crypto holdings. Purporting to provide protection, the letters instruct users to scan a QR codeโ€”an action some critique as a flawed security protocol. One commenter humorously noted, "Sending letters to protect air-gapped wallets is peak comedy."

Information Trafficking Concerns

A new user board comment emphasizes the seriousness of the situation: "The QR code is only one part of the attack treat it as an address-opsec event." This suggests that perpetrators may possess a list linking physical addresses to individuals interested in hardware wallets. Many have been cautioning friends and family against engaging with subsequent calls or packages. Moreover, Coinkite reiterated they will never initiate such correspondence, highlighting the importance of verifying the sources of any communications.

Trending User Reactions

  1. Skepticism: Recipients are registering disbelief at the audacity behind the scam. One person quipped, "I got one last week. Knew it was BS and chuckled."

  2. Vigilance: As awareness grows, people recognize that bona fide companies do not request actions through letters.

  3. Security Discussions: Comments signal heightened awareness of digital security, with many urging caution. A community member warned, "Stay safe and donโ€™t scan or open any links. Keep your keys offline!"

Key Observations

  • ๐Ÿ” The current phishing attempts reflect major vulnerabilities from past breaches.

  • โš ๏ธ Established companies would never ask for sensitive actions through physical mail.

  • ๐Ÿ’ฌ A user pointed out, "Proper post-quantum solution will take years to implement," underlining ongoing technical challenges.

The Future of Crypto Security

In light of the snail mail scam, experts predict more advanced phishing attempts may arise. Cybercriminals are quick to adapt; estimates suggest around 60% of attacks could shift to physical mail as individuals enhance the protection of their online assets. This could lead to a surge in impersonations of credible figures in the crypto realm. Users must remain alert and educate themselves on solid security tactics as the threat landscape evolves.

Echoes Through Time

This can be seen as a modern parallel to confidence schemes from the advent of the telephone era. Just as early phone scammers exploited new technology to manipulate people, todayโ€™s con artists utilize advanced communication methods to tap into vulnerabilities. The lessons from past frauds strongly reinforce the need for skepticism when it comes to safeguarding valuable assets, whether they be crypto wallets, keys, or sensitive data.