Tracking Short Lived Domains Used in QR Phishing

QR phishing, or “quishing,” has rapidly emerged as a major threat vector, leveraging the widespread adoption of QR codes to trick users into visiting malicious domains. Attackers embed QR codes in emails, printed materials, or even public advertisements, enticing users to scan them with mobile devices that often bypass traditional email security filters. A critical enabler of these attacks is the use of short-lived domains—websites that are registered, activated, and abandoned within hours or days—to evade detection and blacklisting. Tracking and investigating these ephemeral domains through DNS forensics is vital for uncovering attacker infrastructure, mitigating risks, and improving threat intelligence.

The first step in tracking short-lived domains used in QR phishing involves recognizing the DNS resolution patterns unique to these operations. Attackers often register new domains specifically for each campaign or even each victim group, using automation to generate and deploy domains on demand. These domains typically exhibit certain telltale characteristics: extremely recent registration dates, low time-to-live (TTL) values on DNS records, initial resolutions to IP addresses within specific hosting providers known for abuse tolerance, and rapid disappearance from the DNS after the campaign ends or is detected. Forensic investigators monitor newly registered domains using threat intelligence feeds, zone file downloads, or real-time monitoring services that provide daily or hourly snapshots of domain registrations.

Passive DNS (pDNS) data is an essential tool in identifying and tracking these domains. Investigators query passive DNS databases to find when a domain was first observed, how long it remained active, which IP addresses it resolved to, and whether it shared infrastructure with other known malicious domains. Domains used in QR phishing often demonstrate highly transient lifespans in passive DNS records, sometimes only a few hours from first resolution to inactivity. By correlating the observed lifespan with known phishing campaign timelines, analysts can tie domains to specific threat actor tactics.

One critical forensic technique involves clustering domains based on shared hosting characteristics. Short-lived phishing domains often resolve to the same IP ranges, ASN (Autonomous System Numbers), or hosting providers. Investigators collect historical and real-time DNS A and AAAA records, noting overlaps in infrastructure. Even if the domains themselves are different, shared hosting details suggest centralized control, revealing broader phishing campaigns and enabling preemptive blocking of related assets. DNS PTR records and reverse lookups can further assist in linking seemingly disparate domains to common back-end systems.

TLS certificate transparency (CT) logs provide another valuable avenue for tracking short-lived domains. Attackers deploying phishing sites often obtain certificates to avoid browser warnings about insecure connections. Even free certificate authorities like Let’s Encrypt require public logging of issued certificates. By monitoring CT logs for newly issued certificates associated with recently registered domains, investigators can discover emerging phishing sites before they are heavily utilized. Extracting domain names from CT logs and correlating them with DNS records allows proactive detection of short-lived domains intended for QR phishing use.

Active DNS probing enhances passive techniques by verifying domain status in near real-time. Forensic teams perform automated DNS lookups against suspected domains, capturing current resolutions, authoritative name servers, and DNS response behavior. Anomalies such as inconsistent answers across lookups, fast-changing IP addresses, or NXDOMAIN responses immediately following initial resolution suggest domain takedown operations or attacker-initiated domain withdrawal after campaign completion. Logging these observations with precise timestamps helps reconstruct the operational timeline of the phishing infrastructure.

Investigators must also analyze the QR code delivery vectors to trace domain usage. In many cases, captured QR codes can be decoded to reveal embedded URLs. Examination of these URLs often uncovers patterns such as embedded tracking parameters, URL shorteners, or intermediate redirection domains used to obscure the final destination. DNS records for all intermediary domains must be collected and correlated to map the full path users would follow after scanning a QR code. Often, attackers use a chain of short-lived redirection domains to further complicate forensic tracking, necessitating recursive DNS and HTTP resolution logging.

In addition to purely technical indicators, forensic analysts can leverage WHOIS information and domain registration artifacts to track and attribute short-lived domains. Although privacy protection services often obscure registrant details, consistent patterns in registrar usage, registration timing, and contact information syntax can expose clusters of domains registered by the same actors. Scraping and analyzing WHOIS records, even when redacted, provides metadata such as registrar name, registration date, expiration date, and name server choice, all of which contribute to building threat actor profiles.

Integration with security information and event management (SIEM) systems enables real-time alerting on the use of suspicious, newly observed domains within an organization’s network. By enriching DNS query logs with threat intelligence about domain freshness, hosting reputation, and registration anomalies, organizations can detect when users scan a malicious QR code and attempt to connect to a phishing site, often before any payload is delivered or credentials are stolen. Rapid correlation between endpoint behavior and DNS activity is crucial for effective containment.

Effective forensic investigation of short-lived domains used in QR phishing also requires partnerships with domain registrars, hosting providers, and takedown organizations. Promptly reporting malicious domains based on DNS forensic evidence can lead to faster takedown, reducing the window of exposure. Building automated feeds that share indicators of compromise (IOCs) such as domain names, IP addresses, and associated certificates with trusted partners amplifies defensive efforts across the broader internet ecosystem.

Ultimately, tracking short-lived domains in QR phishing campaigns demands a fusion of passive and active DNS techniques, infrastructure correlation, certificate transparency monitoring, and endpoint forensic analysis. Given the speed and agility with which attackers deploy and discard these domains, forensic investigations must operate with equal urgency, leveraging automation, intelligence sharing, and advanced analytics to outpace the threat. Mastering these techniques enables organizations to detect QR phishing attacks earlier, disrupt attacker infrastructure, and protect users from increasingly sophisticated social engineering threats delivered through seemingly innocuous QR codes.

QR phishing, or “quishing,” has rapidly emerged as a major threat vector, leveraging the widespread adoption of QR codes to trick users into visiting malicious domains. Attackers embed QR codes in emails, printed materials, or even public advertisements, enticing users to scan them with mobile devices that often bypass traditional email security filters. A critical…