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Visualizing a String of Paerls

Researchers from the Cisco Talos Security Intelligence and Research Team recently discovered an elaborate attack dubbed the String of Paerls. The attack, a combined spearphishing and exploit attempt, was able to bypass most antivirus engines and used a targeted phishing email that included a malicious Word document attachment. Upon opening the Word attachment, a macro downloaded and launched an executable on the victim’s machine, which then called out to command and control servers.

In the graphic below you can see an illustration of each of the major steps of the attack. A common thread is that Cisco security provides protection against attacks like this one using the approach of integrated threat defense. Specifically, Advanced Malware Protection tools were used throughout the discovery and analysis process to expose the exploit.


For a complete play-by-play of this attack, read the String of Paerls blog post from Talos. For more about integrated threat defense in our products, see the new Cisco ASA with FirePOWER Services.

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Shellshock Exploits in the Wild

This post was authored by Joel Esler & Martin Lee.

The recently discovered Bash vulnerability (CVE-2014-6271) potentially allows attackers to execute code on vulnerable systems. We have already blogged about the issue and provided more technical detail in a further blog. The rapid release of IPS signatures for our platforms allowed us to follow very quickly, the attempts at exploitation of the vulnerability in the wild.

For further details of our response to the issue, please see the Event Response Page.
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Another Major Vulnerability Bashes Systems

Vulnerabilities that permit remote network attacks against ubiquitous software components are the nightmares of security professionals. On 24 September the presence of a new vulnerability, CVE-2014-6271 in Bash shell allowing remote code execution was disclosed.
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Threat Spotlight: “Kyle and Stan” Malvertising Network 9 Times Larger Than Expected

This post was authored by Armin Pelkmann.

On September 8th, Cisco’s Talos Security Intelligence & Research Group unveiled the existence of the “Kyle and Stan” Malvertisement Network. The network was responsible for placing malicious advertisements on big websites like,,, and 70 other domains. As it turns out, this was just the tip of the iceberg. Ongoing research now reveals the real size of the attackers’ network is 9 times larger than reported in our first blog. For more details, read the Kyle and Stan Blog.

The infographic below illustrates how much more of the malvertisement network was uncovered in comparison to our first assessment. We have now isolated 6491 domains sharing the same infrastructure. This is over 9 times the previously mentioned 703 domains.  We have observed and analyzed 31151 connections made to these domains. This equals over 3 times the amount of connections previously observed. The increase in connections is most likely not proportional to the domains due to the fact that a long time that has passed since the initial attacks.


The discovery difference from the previous blog to this one in raw numbers. With more than 3-times the now observed connections and over 9-times the revealed malicious domains, this malvertising network is of unusually massive proportions.

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Threat Spotlight: “Kyle and Stan” Malvertising Network Threatens Windows and Mac Users With Mutating Malware

This post was authored by Shaun Hurley, David McDaniel and Armin Pelkmann.

Update 2014-09-22: Updates on this threat can be found here

img_MetricsHave you visited,,,, or any of the 74 domains listed below lately? If the answer is yes, then you may have been a victim to the “Kyle and Stan” Malvertising Network that distributes sophisticated, mutating malware for Windows and even Macs.

Table of contents

Attack in a Nutshell
Technical Breakdown
Reversing of the Mac Malware
Reversing of the Windows Malware
Protecting Users Against These Threats

Malvertising is a short form for “malicious advertising.” The idea is very simple: use online advertising to spread malware. Read More »

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