Email bombs exploit lax authentication in Zendesk

(krebsonsecurity.com)

62 points | by todsacerdoti 18 hours ago ago

12 comments

  • fckgw 14 hours ago

    If you start getting an email bombed out of nowhere, being signed up for hundreds of newsletters or other email notifications, take a quick look at your credit card statements for any unknown purchases. Email bombs are often used by card thieves to hide legitimate purchase notifcation email from retailers when they use your stolen creds.

    • mcast 12 hours ago

      Better yet, setup transaction alerts on all your credit cards, and use a budgeting app like Monarch/YNAB to review all your household transactions each month or receive weekly email summaries.

      • YeBanKo 7 hours ago

        > Monarch/YNAB

        Yeah, right. Let some thirds party app collect all your info in their secure cloud. Do you also give Monarch login to your bank account?

    • OptionOfT 13 hours ago

      Another reason to actually get your credit card statement via snail-mail.

      I understand it is wasteful, but I go on an evening walk and pick up the mail.

      The effort for me to pick up the mail and read my credit card statement is actually quite nice.

      It doesn't require you to sign in, and search my house for my phone or my YubiKey, it doesn't prompt me for other credit card offers, doesn't require me to download a PDF reader.

  • ianhawes 14 hours ago

    Brian Krebs is a saint for being the perennial punching bag and target of cybercriminals but continuing to publish important information independently.

  • vachina 13 hours ago

    This attack is called email amplification. Any open form that triggers email sending is vulnerable. Fortunately these bots are pretty basic in my experience, putting a captcha (or anything unexpected) in front is enough to stop these bots.

  • bombcar 14 hours ago

    You know, combing "bomb" with LAX makes me think really different things for awhile until my parser finally woke up ...

  • dboreham 16 hours ago

    Ah. This explains a bunch of odd emails I received all at the same time last week.

    • Volundr 15 hours ago

      Yeah I got enough of these from discord, that I emailed their abuse@ and put in a support ticket, but they ignored me. Nice to have it confirmed. I ended up doing a password rotation on the off chance it was me.

    • Ekaros 15 hours ago

      I was kinda confused why I got one from company that really doesn't even operate here and what was the vector with it...

    • whatamidoingyo 15 hours ago

      Yeah, I got like 50 from bugcrowd. I figured someone found a bug somewhere, lol.

  • bgc 14 hours ago

    Another fun Zendesk “feature,” that, to my knowledge, has never been fixed is if you CC it on a thread with any other email address that auto-replies, it will get stuck in a loop and ping-pong emails back and forth until the mailbox fills up.