ASCII smuggling crosses over from AI prompt injection to phishing evasion

    Date: 09/04/2026

    Severity: High

    Summary

    Researchers uncovered a high-volume phishing campaign that repurposed ASCII smuggling may be induced to follow threat actor-controlled instructions, an AI prompt-injection evasion technique for email filter evasion. Attackers inserted invisible Unicode Tag characters into financial keywords to bypass keyword-, ML-, and NLP-based phishing detection while luring victims with business funding and credit offers. The campaign, linked to a broader Active Campaign-delivered phishing operation, demonstrates how AI-era evasion techniques can cross into traditional social engineering and credential-harvesting attacks. 

    Indicators of Compromise (IOC) List 

    Domain/URLs

    guardiangrowthfunding.com

    digitalcapitalboost.com

    thebusinessloanexpress.com

    yourlocfunding.com

    advancefundingboost.com

    guardiancapitalway.com

    harboradvancefunding.com

    unitedfundingwave.com

    directcapitalboost.com

    onlinedirectfinance.com

    catalystcapitalharbor.com

    rocketboostfunding.com

    digitalrushcapital.com

    guardianloccapital.com

    guardianlocchoice.com

    ourbusinessloans.com

    directcapitalpulse.com

    catalystboostfunding.com

    elevatecapitalrush.com

    fundingexpresscapital.com

    Gurucul Threat Detection and Incident Response (TDIR) Queries for Detection

    Detection Query 1 :

    domainname like "catalystcapitalharbor.com" or url like "catalystcapitalharbor.com" or siteurl like "catalystcapitalharbor.com" or domainname like "yourlocfunding.com" or url like "yourlocfunding.com" or siteurl like "yourlocfunding.com" or domainname like "guardianlocchoice.com" or url like "guardianlocchoice.com" or siteurl like "guardianlocchoice.com" or domainname like "advancefundingboost.com" or url like "advancefundingboost.com" or siteurl like "advancefundingboost.com" or domainname like "digitalcapitalboost.com" or url like "digitalcapitalboost.com" or siteurl like "digitalcapitalboost.com" or domainname like "digitalrushcapital.com" or url like "digitalrushcapital.com" or siteurl like "digitalrushcapital.com" or domainname like "guardiangrowthfunding.com" or url like "guardiangrowthfunding.com" or siteurl like "guardiangrowthfunding.com" or domainname like "unitedfundingwave.com" or url like "unitedfundingwave.com" or siteurl like "unitedfundingwave.com" or domainname like "elevatecapitalrush.com" or url like "elevatecapitalrush.com" or siteurl like "elevatecapitalrush.com" or domainname like "onlinedirectfinance.com" or url like "onlinedirectfinance.com" or siteurl like "onlinedirectfinance.com" or domainname like "fundingexpresscapital.com" or url like "fundingexpresscapital.com" or siteurl like "fundingexpresscapital.com" or domainname like "rocketboostfunding.com" or url like "rocketboostfunding.com" or siteurl like "rocketboostfunding.com" or domainname like "catalystboostfunding.com" or url like "catalystboostfunding.com" or siteurl like "catalystboostfunding.com" or domainname like "thebusinessloanexpress.com" or url like "thebusinessloanexpress.com" or siteurl like "thebusinessloanexpress.com" or domainname like "directcapitalpulse.com" or url like "directcapitalpulse.com" or siteurl like "directcapitalpulse.com" or domainname like "harboradvancefunding.com" or url like "harboradvancefunding.com" or siteurl like "harboradvancefunding.com" or domainname like "directcapitalboost.com" or url like "directcapitalboost.com" or siteurl like "directcapitalboost.com" or domainname like "guardianloccapital.com" or url like "guardianloccapital.com" or siteurl like "guardianloccapital.com" or domainname like "guardiancapitalway.com" or url like "guardiancapitalway.com" or siteurl like "guardiancapitalway.com" or domainname like "ourbusinessloans.com" or url like "ourbusinessloans.com" or siteurl like "ourbusinessloans.com"

    Reference: 

    https://www.microsoft.com/en-us/security/blog/2026/09/03/ascii-smuggling-crosses-over-from-ai-prompt-injection-to-phishing-evasion/             


    Tags

    MalwareThreat ActorPhishingAIPrompt InjectionSocial EngineeringCredential HarvestingFinancial Services

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