Wednesday, March 29, 2017

Vulnerability Spotlight: Exploiting Network Time Protocol Origin Timestamp Check Denial of Service Vulnerability

Vulnerabilities discovered by Matthew Van Gundy from Cisco ASIG


Overview



As a member of the Linux Foundation Core Infrastructure Initiative, Cisco is contributing to the CII effort by evaluating the Network Time Protocol daemon (ntpd) for security defects. We previously identified a series of vulnerabilities in the Network Time Protocol daemon; through our continued research we have identified a further vulnerabilities in the software. This vulnerability results in a denial of service attack against peers due to the origin timestamp check functionality. The attacker does not need to be authenticated in order to exploit the vulnerability.

The ntpd daemon uses the Network Time Protocol for clock synchronization between computer systems and as such, plays a vital role in maintaining system integrity.

Monday, March 27, 2017

Vulnerability Spotlight: Certificate Validation Flaw in Apple macOS and iOS Identified and Patched

Most people don't give much thought to what happens when you connect to your bank's website or log in to your email account. For most people, securely connecting to a website seems as simple as checking to make sure the little padlock in the address bar is present. However, in the background there are many different steps that are taken to ensure you are safely and securely connecting to the websites that claim they are who they are. This process includes certificate validation, or making sure that the servers that users are connecting to present "identification" showing they are legitimate. This helps to protect users from fraudulent servers that might otherwise steal sensitive information.

Due to the sensitive nature of this process, software vulnerabilities that adversely impact the security of certificate validation could have major consequences. Unfortunately, digital systems are complex and bugs are an inevitable reality in software development. Identifying vulnerabilities and responsibly disclosing them improves the security of the internet by eliminating potential attack vectors. Talos is committed to improving the overall security of the internet and today we are disclosing TALOS-2017-0296 (CVE-2017-2485), a remote code execution vulnerability in the X.509 certificate validation functionality of Apple macOS and iOS. This vulnerability has been responsibly disclosed to Apple and software updates have been released that address this issue for both macOS and iOS.

Friday, March 24, 2017

Threat Round-up for the Week of Mar 20 - Mar 24

Today, Talos is publishing a glimpse into the most prevalent threats we've observed over the past week. As with previous round-ups, this post isn't meant to be an in-depth analysis. Instead, this post will summarize the threats we've observed by highlighting key behavior characteristics, indicators of compromise, and how our customers are automatically protected from these threats.

As a reminder, the information provided for the following threats in this post is non-exhaustive and current as of date of publication. Detection and coverage for the following threats is subject to updates pending additional threat or vulnerability analysis. For the most current information, please refer to your FireSIGHT Management Center, Snort.org, or ClamAV.net.

Thursday, March 23, 2017

How Malformed RTF Defeats Security Engines

This post is authored by Paul Rascagneres with contributions from Alex McDonnell

Executive Summary


Talos has discovered a new spam campaign used to infect targets with the well known Loki Bot stealer. The infection vector is an RTF document abusing an old exploit (CVE-2012-1856), however the most interesting part is the effort put into the generation of the RTF. The document contains several malformations designed to defeat security engines and parsers. The attacker has gone out of their way to attempt to evade content inspection devices like AV or network security devices. According to VirusTotal, the initial detection rate of a malicious RTF document recovered from a recent spam campaign is only 3 out of 45 available engines.

Despite the known vulnerability, many security products fail to identify the exploit because they are unable to correctly classify the RTF file format and scan the embedded OLE document within in the RTF. Even open-source parsers such as rtfobj.py from oletools have difficulties extracting the embedded OLE:


This article explains how the malware author modified the RTF file in order to bypass security protection and frustrate malware researchers.


Wednesday, March 22, 2017

Vulnerability Spotlight: Code Execution Vulnerability in LabVIEW

Vulnerability discovered by Cory Duplantis of Cisco Talos.

Overview


LabVIEW is a system design and development platform released by National Instruments. The software is widely used to create applications for data acquisition, instrument control and industrial automation. Talos is disclosing the presence of a code execution vulnerability and a memory corruption vulnerability which can be triggered by opening specially crafted VI files, the proprietary file format used by LabVIEW. National Instruments have released a patch, LabVIEW 2016 f2 which should be applied.

Monday, March 20, 2017

Necurs Diversifies Its Portfolio

The post was authored by Sean Baird, Edmund Brumaghin and Earl Carter, with contributions from Jaeson Schultz.

Executive Summary


The Necurs botnet is the largest spam botnet in the world. Over the past year it has been used primarily for the distribution of Locky ransomware and Dridex. Earlier this year, we wrote about how the Necurs botnet went offline and seemingly disappeared, taking most of the high volume Locky malspam with it. Talos recently identified a significant increase in the amount of spam emails originating from the Necurs botnet, indicating that it may have come back to life, but rather than distributing malware in the form of malicious attachments, it appears to have shifted back to penny stock pump-and-dump messages. This is not the first time that Necurs has been used to send high volume pump-and-dump emails. In analyzing previous telemetry data associated with these campaigns, we identified a similar campaign on December 20, 2016 shortly before the Necurs botnet went offline for an extended period. This strategic divergence from the distribution of malware may be indicative of a change in the way that attackers are attempting to economically leverage this botnet.

Friday, March 17, 2017

Threat Round-up for the Week of Mar 13 - Mar 17

Today, Talos is publishing a glimpse into the most prevalent threats we've observed over the past week. As with previous round-ups, this post isn't meant to be an in-depth analysis. Instead, this post will summarize the threats we've observed by highlighting key behavior characteristics, indicators of compromise, and how our customers are automatically protected from these threats.

As a reminder, the information provided for the following threats in this post is non-exhaustive and current as of date of publication. Detection and coverage for the following threats is subject to updates pending additional threat or vulnerability analysis. For the most current information, please refer to your FireSIGHT Management Center, Snort.org, or ClamAV.net.

Tuesday, March 14, 2017

Microsoft Patch Tuesday - March 2017

Following a sparse February patch Tuesday, today’s March release brings a bumper crop of fixed vulnerabilities: 17 bulletins covering 140 different vulnerabilities, 47 of which are rated as critical. The critical vulnerabilities affect Internet Explorer, Edge, Hyper-V, Windows PDF Library, Microsoft SMB Server, Uniscribe, Microsoft Graphics Component, Adobe Flash Player and Microsoft Windows. 92 vulnerabilities are rated as important, additionally affecting Active Directory Federation Services, DirectShow, Internet Information Services, Microsoft Exchange Server, Microsoft Office, Microsoft XML Core Services, Windows DVD Maker, Windows Kernel, Windows Kernel-Mode Drivers.

Friday, March 10, 2017

Threat Round-up for the Week of Mar 6 - Mar 10

Today, Talos is publishing a glimpse into the most prevalent threats we've observed over the past week. As with our previous threat round-up, this post isn't meant to be an in-depth analysis. Instead, this post will summarize the threats we've observed by highlighting key behavior characteristics, indicators of compromise, and how our customers are automatically protected from these threats.

As a reminder, the information provided for the following threats in this post is non-exhaustive and current as of date of publication. Detection and coverage for the following threats is subject to updates pending additional threat or vulnerability analysis. For the most current information, please refer to your FireSIGHT Management Center, Snort.org, or ClamAV.net.

Thursday, March 9, 2017

Vulnerability Spotlight: R - PDF LoadEncoding Code Execution Vulnerability

Vulnerability Discovered by Cory Duplantis of Cisco Talos

Overview

Talos is disclosing TALOS-2016-0227 / CVE-2016-8714 which is a buffer overflow vulnerability in the LoadEncoding functionality of the R programming language version 3.3.0. The R programming language is commonly used in statistical computing and is supported by the R Foundation for Statistical Computing. R is praised for having a large variety of statistical and graphical features. The vulnerability is specifically related to the creation of a PDF document.