Social Engineering Attack Against Adobe Reader

April 1, 2010

Social engineering is the act of manipulating people into performing actions or divulging confidential information, rather than by breaking in or using technical hacking techniques.

Didier Stevens recently demonstrated how to use social engineering techniques to entice end user and execute arbitrary code in Adobe Reader. The original blog post can be found here. Given the popularity of Adobe Reader, it is a great example showing how social engineering attacks can affect our daily lives.

Adobe Reader does not allow embedded executables to be extracted and executed directly. To bypassed the restriction, the first thing (in Windows) to do is running cmd.exe. This can be achieved by calling (/Launch /Action). The only thing preventing cmd.exe from execution is a dialog box:

Using social engineering techniques, the author replaced the warning message to this:

Once the targeted user clicks the "Open" button, the cmd.exe will be launched. At this point it is up to the PDF author's creativity to perform additional malicious actions, as cmd.exe can be used to run embedded executables in the PDF file.

SonicWALL has released an IPS signature to detect and block PDF files utilizing launch action. The signature is listed below:

  • 4907 Suspicious Launch Action in PDF Document

Please note since usage of launch action is legitimate and defined in PDF specs, the signature is set to low priority.