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Threat Spotlight: A String of ‘Paerls’, Part One

June 30, 2014 at 7:00 am PST

This post was co-authored by Jaeson SchultzJoel Esler, and Richard Harman

Update 7-8-14: Part 2 can be found hereVRT / TRAC

This is part one in a two-part series due to the sheer amount of data we found on this threat and threat actor. This particular attack was a combined spearphishing and exploit attempt. As we’ve seen in the past, this can be a very effective combination.

In this specific example the attackers targeted a feature within Microsoft Word — Visual Basic Scripting for Applications. While basic, the Office Macro attack vector is obviously still working quite effectively.  When the victim opens the Word document, an On-Open macro fires, which results in downloading an executable and launching it on the victim’s machine. This threat actor has particularly lavish tastes.  This threat actor seem to target high-profile, money-rich industries such as banking, oil, television, and jewelry.

Discovering the threat

The VRT has hundreds of feeds of raw threat intelligence, ranging from suspicious URLs, files, hashes, etc.  We take that intelligence data and apply  selection logic to it to identify samples that are worthy of review.  Using various methods from machine learning to dynamic sandbox analysis, we gather details about the samples -- producing indicator of  compromise (IOC), and alerts made up of multiple IOCs.

During our analysis we took the last 45 days’ worth of samples, and clustered them together based on a matching set of alert criteria.  This process reduced over a million detailed sample reports to just over 15 thousand sample clusters that exhibit similar behavior.  Using this pattern of similar behavior, we were capable of identifying families of malware.  This led us to discover a Microsoft Word document that downloaded and executed a secondary sample, which began beaconing to a command and control server.

The Malicious Word documents & Associated Phishing campaign

The attacks we uncovered are an extremely targeted spear phish in the form of an invoice, purchase order, or receipt, written specifically for the recipient.  For instance, the following is an example message we observed that purportedly came from “Maesrk”, the shipping company.

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Massive Increase in Reconnaissance Activity – Precursor to Attack?

November 4, 2013 at 1:15 pm PST

Update 2013-11-12Watch our youtube discussion

Update 2013-11-05: Upon further examination of the traffic we can confirm that a large percentage is destined for TCP port 445. This is indicative of someone looking for nodes running SMB/DCERPC. With that in mind it is extremely likely someone is looking for vulnerable windows machines or it is quite possible that the “soon to be” attackers are looking for boxes compromised by a specific malware variant.

On 2013-11-02 at 01:00 UTC Cisco saw a massive spike in TCP source port zero traffic for three hours. This was the largest spike of reconnaissance activity we’ve seen this year. TCP source port zero is a reserved port according to the RFC and it should not be used. Customers who see port zero activity on their network should consider the traffic suspicious and investigate the source.

pscan

This graph displays the magnitude of the number of sensors logging this activity. Normally we see a magnitude of less than 20, this increased five fold on 2013-11-02. There was also an associated massive increase in the volume of traffic observed by signature 24199-0.

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Scope of ‘KeyBoy’ Targeted Malware Attacks

On June 6, 2013, malwaretracker.com released an analysis of Microsoft Office-based malware that was exploiting a previously unknown vulnerability that was patched by MS12-060. The samples provided were alleged to be targeting Tibetan and Chinese Pro-Democracy Activists. On June 7, 2013, Rapid7 released an analysis of malware dubbed ‘KeyBoy,’ also exploiting unknown vulnerabilities in Microsoft Office, similarly patched by MS12-060, but allegedly targeting interests in Vietnam and India. The indicators of compromise (IoCs) listed by Rapid7 match some of the indicators of compromise listed previously by malwaretracker.com.

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Debugger Inception – The Scriptable Debugger Within The Debugger

I recently began working on a toolset to aid with analyzing binary protocols and I decided to use it as an exercise to get more familiar with the Immunity Debugger. I have been using Windbg for a while now, however, I was constantly reading articles discussing how great Immunity Debugger is for exploit development and I had been meaning to take the time to become more familiar with it.

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Post-Exploitation Techniques from Black Hat 2011

In many exploit scenarios, an attacker finds a target and, if possible, establishes remote control over the system through known or unknown exploits. Whether the attacker uses a buffer overflow, insecure configuration, phishing for credentials, or cookie-stealing, the goal is clear: get a remote shell and gain complete control. Then what?

It is this post-exploitation environment that has interested me at this year’s Black Hat 2011. Several talks and trainings discuss post-exploitation techniques, and I’d like to share them in the interest of research – and defense.

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