Canva Infrastructure Abuse

  1name: "Canva Infrastructure Abuse"
  2description: "A fraudulent invoice/receipt found in the body of the message sent by exploiting Canva's design sharing feature."
  3type: "rule"
  4severity: "medium"
  5source: |
  6  type.inbound
  7  and length(attachments) == 1
  8  and sender.email.domain.root_domain in ("canva.com")
  9  and strings.ilike(body.html.display_text, "*take a look at the design*")
 10  and (
 11    (
 12      // icontains a phone number
 13      (
 14        regex.icontains(strings.replace_confusables(body.current_thread.text),
 15                        '.*\+?([ilo0-9]{1}.)?\(?[ilo0-9]{3}?\)?.[ilo0-9]{3}.?[ilo0-9]{4}.*\n'
 16        )
 17        or regex.icontains(strings.replace_confusables(body.current_thread.text),
 18                           '.*\+[ilo0-9]{1,3}[ilo0-9]{10}.*\n'
 19        )
 20        or // +12028001238
 21   regex.icontains(strings.replace_confusables(body.current_thread.text),
 22                   '.*[ilo0-9]{3}\.[ilo0-9]{3}\.[ilo0-9]{4}.*\n'
 23        )
 24        or // 202-800-1238
 25   regex.icontains(strings.replace_confusables(body.current_thread.text),
 26                   '.*[ilo0-9]{3}-[ilo0-9]{3}-[ilo0-9]{4}.*\n'
 27        )
 28        or // (202) 800-1238
 29   regex.icontains(strings.replace_confusables(body.current_thread.text),
 30                   '.*\([ilo0-9]{3}\)\s[ilo0-9]{3}-[ilo0-9]{4}.*\n'
 31        )
 32        or // (202)-800-1238
 33   regex.icontains(strings.replace_confusables(body.current_thread.text),
 34                   '.*\([ilo0-9]{3}\)-[ilo0-9]{3}-[ilo0-9]{4}.*\n'
 35        )
 36        or ( // 8123456789
 37          regex.icontains(strings.replace_confusables(body.current_thread.text),
 38                          '.*8[ilo0-9]{9}.*\n'
 39          )
 40          and regex.icontains(strings.replace_confusables(body.current_thread.text
 41                              ),
 42                              '\+[1l]'
 43          )
 44        )
 45      )
 46      and (
 47        (
 48          4 of (
 49            strings.ilike(body.html.inner_text, '*you did not*'),
 50            strings.ilike(body.html.inner_text, '*is not for*'),
 51            strings.ilike(body.html.inner_text, '*done by you*'),
 52            regex.icontains(body.html.inner_text, "didn\'t ma[kd]e this"),
 53            strings.ilike(body.html.inner_text, '*Fruad Alert*'),
 54            strings.ilike(body.html.inner_text, '*Fraud Alert*'),
 55            strings.ilike(body.html.inner_text, '*fraudulent*'),
 56            strings.ilike(body.html.inner_text, '*using your PayPal*'),
 57            strings.ilike(body.html.inner_text, '*subscription*'),
 58            strings.ilike(body.html.inner_text, '*antivirus*'),
 59            strings.ilike(body.html.inner_text, '*order*'),
 60            strings.ilike(body.html.inner_text, '*support*'),
 61            strings.ilike(body.html.inner_text, '*sincerely apologize*'),
 62            strings.ilike(body.html.inner_text, '*receipt*'),
 63            strings.ilike(body.html.inner_text, '*invoice*'),
 64            strings.ilike(body.html.inner_text, '*Purchase*'),
 65            strings.ilike(body.html.inner_text, '*transaction*'),
 66            strings.ilike(body.html.inner_text, '*Market*Value*'),
 67            strings.ilike(body.html.inner_text, '*BTC*'),
 68            strings.ilike(body.html.inner_text, '*call*'),
 69            strings.ilike(body.html.inner_text, '*get in touch with our*'),
 70            strings.ilike(body.html.inner_text, '*quickly inform*'),
 71            strings.ilike(body.html.inner_text, '*quickly reach *'),
 72            strings.ilike(body.html.inner_text, '*detected unusual transactions*'),
 73            strings.ilike(body.html.inner_text, '*without your authorization*'),
 74            strings.ilike(body.html.inner_text, '*cancel*'),
 75            strings.ilike(body.html.inner_text, '*renew*'),
 76            strings.ilike(body.html.inner_text, '*refund*'),
 77            strings.ilike(body.html.inner_text, '*+1*'),
 78            regex.icontains(body.html.inner_text, 'help.{0,3}desk'),
 79            strings.ilike(body.html.inner_text, '* your funds*'),
 80            strings.ilike(body.html.inner_text, '* your checking*'),
 81            strings.ilike(body.html.inner_text, '* your saving*'),
 82            strings.ilike(body.html.inner_text, '*transfer*'),
 83            strings.ilike(body.html.inner_text, '*secure your account*'),
 84            strings.ilike(body.html.inner_text, '*recover your*'),
 85            strings.ilike(body.html.inner_text, '*unusual activity*'),
 86            strings.ilike(body.html.inner_text, '*suspicious transaction*'),
 87            strings.ilike(body.html.inner_text, '*transaction history*'),
 88            strings.ilike(body.html.inner_text, '*please ignore this*'),
 89            strings.ilike(body.html.inner_text, '*report activity*'),
 90          )
 91        )
 92        or regex.icontains(body.current_thread.text,
 93                           'note from.{0,50}(?:call|reach|contact|paypal)'
 94        )
 95        or any(ml.nlu_classifier(body.current_thread.text).intents,
 96               .name == "callback_scam"
 97        )
 98        or (
 99          // Unicode confusables words obfuscated in note
100          regex.icontains(body.html.inner_text,
101                          '\+𝟭|𝗽𝗮𝘆𝗺𝗲𝗻𝘁|𝗛𝗲𝗹𝗽 𝗗𝗲𝘀𝗸|𝗿𝗲𝗳𝘂𝗻𝗱|𝗮𝗻𝘁𝗶𝘃𝗶𝗿𝘂𝘀|𝗰𝗮𝗹𝗹|𝗰𝗮𝗻𝗰𝗲𝗹'
102          )
103        )
104        or strings.ilike(body.html.inner_text, '*kindly*')
105      )
106    )
107  )  
108
109attack_types:
110  - "BEC/Fraud"
111  - "Callback Phishing"
112tactics_and_techniques:
113  - "Social engineering"
114  - "Impersonation: Brand"
115  - "Impersonation: Employee"
116  - "Free email provider"
117detection_methods:
118  - "Natural Language Understanding"
119  - "Sender analysis"
120  - "Content analysis"
121id: "b69fdb5c-e0c2-5c77-9280-2e473500b915"