Adobe’s latest Flash zero-day targeted Microsoft Office users

The zero-day flaw in Flash Player that Adobe patched on Thursday targeted Microsoft Office users, according to security firm FireEye

The zero-day flaw in Flash Player that Adobe patched on Thursday targeted Microsoft Office users, according to security firm FireEye.

If your organisation is running Windows, Microsoft Office, and Flash Player, then Adobe’s Flash Player patch from last Thursday should be a top priority.

According to FireEye security researcher Genwei Jiang, Adobe rushed out a patch for Flash Player just four days after he reported that attackers were exploiting the bug (CVE-2016-4117).

Adobe said last week that it had received a report from FireEye that a zero-day bug for which it had no patch had been exploited in the wild, but besides disclosing that it could allow attackers to take control of a vulnerable system, it hadn’t it explained how the attack was deployed.

Adobe did however produce the patch quickly. Google offers vendors three months to patch any bug that it’s Project Zero team discovers before disclosing details about them.

FireEye’s Jiang has now detailed that the Flash exploit was embedded in a Microsoft Office document and that the attackers were targeting organisations that run Windows, Office and Flash.

The attackers sent booby-trapped Office files to targets in the hope that the file would be opened, however since they had also hosted the document on their own server, it could arrive as a link. If the target opened the document or the link, the exploit would be downloaded and executed from the attacker’s server.

Even though the attack didn’t rely on a vulnerability in any of Microsoft’s Office products, Office was a conduit to the user since it is able to render Flash files.

Oddly, it seems the attackers narrowed their tools to targets that had recently updated Flash Player.

According to Jiang, if the user was running a version of Flash Player older than — which was released before April — the malware would abort the operation. For any new version of Flash, the exploit would run embedded native shellcode and then download a second piece of malware that displays a fake document.

FireEye’s Jiang recommended that enterprise users could consider deploying Microsoft’s Enhanced Mitigation Experience Toolkit (EMET) to make it more difficult for attackers to exploit this vulnerability. Otherwise, as Adobe has already recommended, Flash users should install the latest version of Flash Player immediately.

The Flash Player bug reported by FireEye was the third zero-day exploit in as many months that was being used by attackers before Adobe could patch the flaw.

It came as Google aired a plan to demote Flash Player as the default media player plugin in Chrome for all but the 10 most popular sites that require Flash to display content by the end of the 2016.

Join the CSO newsletter!

Error: Please check your email address.

Tags Googleflash playeradobeFireEyepatch managementmicrosoft officeoffice filesTraps

More about FireEyeGoogleMicrosoftToolkit

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Liam Tung

Latest Videos

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

  • 150x50

    IDG Live Webinar:The right collaboration strategy will help your business take flight

    Speakers - Mike Harris, Engineering Services Manager, Jetstar - Christopher Johnson, IT Director APAC, 20th Century Fox - Brent Maxwell, Director of Information Systems, THE ICONIC - IDG MC/Moderator Anthony Caruana

    Play Video

More videos

Blog Posts