4 ms·
We had an employee compromised by a similar attack-executable linked in a Pdf. Basic flow was-phisher asked employee to sign a document relating to customs. Th
by zrobotics 4y ago
We had an employee compromised by a similar attack-executable linked in a Pdf.
Basic flow was-phisher asked employee to sign a document relating to customs. The phisher had gathered that this employee works with shipping claims and returns, and surmised that they need to deal with customs documents requiring signature. There was a link to an exe hosted on a European cloud service in the PDF titled "install fake signature certificate company to sign this document". This directed to a download of a basic ransomware executable. This did get past our AV to the point of encrypting the employee's machine, but thankfully was blocked from spreading to the rest of the network.
The employee's machine was toast, but I was able to restore from the prior day's backup and no major harm occurred. I was able to see the phishing attack since we use gsuite email so the ransom ware didn't erase the employee's inbox, but they did lose a half-day work and I updated our training. The attack itself was clever from a social engineering perspective, but the technical exploit was something any script kiddy could have downloaded from the open web, nothing advanced at all. But Gmail doesn't always scan links in PDFs, so a clever ruse was able to bypass Google's scanning as well as our local scanning.
- stef25 4y agoThe employee clicked on a link asking them to install a security certificate and completed the install?
- chinathrow 4y agoThe way I read it, the employee installed/ran an .exe.
- chinathrow 4y agoGreat write-up. What I don't understand: Why do you let your users run downloaded executables, at all?
- zrobotics 4y agoThis was a bypass of our security process, ideally they shouldn't be able to. However, since it wasn't downloaded through the browser, our security solution didn't intercept it. That was a whole other issue, and I was not at all pleased with the vendor. Unfortunately, I can't name-and-shame, but we also switched vendors after that issue. And due to a legacy system, we can't rely on windows UAC to prevent these attacks either, this user needed to have a local admin account. Yes, this is a security issue in itself, but needs must.