Trend Micro Facebook TrendLabs Twitter Malware Blog RSS Feed You Tube - Trend Micro
Search our blog:

  • Mobile Vulnerabilities

  • Zero-Day Alerts

  • Recent Posts

  • Calendar

    August 2015
    S M T W T F S
    « Jul    
  • Email Subscription

  • About Us

    Earlier the other day, I was browsing through the Yahoo! PH site and the Yahoo! Purple Hunt 2.0 ad caught my attention.

    Curious, I clicked the ad and found my browser downloading a suspicious file named

    Apparently, this ad redirected me to a randomly generated URL similar to the following, which unfortunately led to the malicious download:

    • hxxp://want6.{BLOCKED}.com/se/3da19bea8f9c03e96c9b1acad9cce5a88a2244f0a34d69
    • hxxp://nose8.{BLOCKED}.com/se/3da19bea8f9c03e96c9b1acad9cce5a88a2244f0a34d69c
    • hxxp://letter6.{BLOCKED}.com/se/3da19bea8f9c03e96c9b1acad9cce5a88a2244f0a34d69c0

    Below is a screenshot of the file download dialog box.

    The downloaded file is detected by Trend Micro as TSPY_PIRMINAY.A. Let’s see how the download took place.

    First, the download only happens once per browser. This means that the malvertisement may have used an IP and user agent filtering process of some sort to prevent multiple downloads, which would make it suspicious to the end user.

    To be able to replicate the malware download from the compromised ad, we used a browser extension that spoofs browser user agents instead of installing different browsers.

    It appears that the advertisement is first redirected to the malware download before it finally brings the browser to the real advertising page. The redirection follows this format for the download link:

    http://{varying string}{random number}.{varying domain}/se/{constant string or guid}/

    We’d like to thank the guys over at Yahoo! Ad Security Ops for swiftly acting on our initial report, taking down the malvertisement so it can no longer harm unsuspecting users.

    Share this article
    Get the latest on malware protection from TrendLabs
    Email this story to a friend   Technorati   NewsVine   MySpace   Google   Live   StumbleUpon


    © Copyright 2013 Trend Micro Inc. All rights reserved. Legal Notice