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Threat Research

  • TeleGrab – Grizzly Attacks on Secure Messaging

    - May 16, 2018 - 1 Comment

    Over the past month-and-a-half, Talos has seen the emergence of a malware that collects cache and key files from end-to-end encrypted instant messaging service Telegram. This malware was first seen on April 4, 2018, with a second variant emerging on April 10.

    While the first version only stole browser credentials and cookies, along with all text files it can find on the system, the second variant added the ability to collect Telegram’s desktop cache and key files, as well as login information for the Steam website.

    Talos intelligence research allowed the identification of the author behind this malware with high confidence. The author posted several YouTube videos with instructions on how to use the Telegram collected files to hijack Telegram sessions and how to package it for distribution.

    The operators of this malware use several pcloud.com hardcoded accounts to store the exfiltrated information. This information is not encrypted, which means that anyone with access to these credentials will have access to the exfiltrated information.

    The malware is mainly targeting Russian-speaking victims, and is intentionally avoiding IP addresses related with anonymizer services.

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  • Vulnerability Spotlight: Multiple Adobe Acrobat Reader DC Vulnerabilities

    - May 15, 2018 - 0 Comments

    Discovered by Aleksandar Nikolic of Cisco Talos

    Overview

    Today, Talos is releasing details of a new vulnerabilities within Adobe Acrobat Reader DC. Adobe Acrobat Reader is the most popular and most feature-rich PDF reader. It has a big user base, is usually a default PDF reader on systems and integrates into web browsers as a plugin for rendering PDFs. As such, tricking a user into visiting a malicious web page or sending a specially crafted email attachment can be enough to trigger this vulnerability.

    A specific Javascript script embedded in a PDF file can cause the document ID field to be used in an unbounded copy operation leading to stack-based buffer overflow when opening a specially crafted PDF document in Adobe Acrobat Reader DC 2018.009.20044. This stack overflow can lead to return address overwrite which can result in arbitrary code execution. In order to trigger this vulnerability, the victim would need to open the malicious file or access a malicious web page.

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  • Threat Roundup for May 04 – 11

    - May 11, 2018 - 0 Comments

    Today, Talos is publishing a glimpse into the most prevalent threats we’ve observed between May 4 and May 11. 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 behavioral characteristics, indicators of compromise, and discussing 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 the 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 Firepower Management Center, Snort.org, or ClamAV.net.

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  • Gandcrab Ransomware Walks its Way onto Compromised Sites

    - May 9, 2018 - 0 Comments

    This blog post authored by Nick Biasini with contributions from Nick Lister and Christopher Marczewski.

    Despite the recent decline in the prevalence of ransomware in the threat landscape, Cisco Talos has been monitoring the now widely distributed ransomware called Gandcrab. Gandcrab uses both traditional spam campaigns, as well as multiple exploit kits, including Rig and Grandsoft. While we’ve seen cryptocurrency miners overtake ransomware as the most popular malware on the threat landscape, Gandcrab is proof that ransomware can still strike at any time.

    While investigating a recent spam campaign Talos found a series of compromised websites that were being used to deliver Gandcrab. This malware is the latest in a long line of examples of why stopping malware distribution is a problem, and shows why securing websites is both an arduous and necessary task. As a clear example of how challenging resolving these issues can be, one of the sites — despite being shut down briefly — was seen serving Gandcrab not once, but twice, over a few days.

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  • Wipers – Destruction as a means to an end

    - May 8, 2018 - 0 Comments

    In a digital era when everything and everyone is connected, malicious actors have the perfect space to perform their activities. During the past few years, organizations have suffered several kinds of attacks that arrived in many shapes and forms. But none have been more impactful than wiper attacks. Attackers who deploy wiper malware have a singular purpose of destroying or disrupting systems and/or data.

    Unlike malware that holds data for ransom (ransomware), when a malicious actor decides to use a wiper in their activities, there is no direct financial motivation. For businesses, this often is the worst kind of attack, since there is no expectation of data recovery.

    Another crucial aspect of a wiper attack is the fear, uncertainty and doubt that it generates. In the past, wiper attacks have been used by malicious actors with a dual purpose: Generate social destabilization while sending a public message, while also destroying all traces of their activities.

    A wiper’s destructive capability can vary, ranging from the overwriting of specific files, to the destruction of the entire filesystem. The amount of data impacted will be a direct consequence of the technique used. Which, of course, will have direct impact on the business — the harder the data/system recovery process becomes, the bigger the business impact.

    The defense against these attacks often falls back to the basics. By having certain protections in place — a tested cyber security incident response plan, a risk-based patch management program, a tested and cyber security-aware business continuity plan, and network and user segmentation on top of the regular software security stack — an organization dramatically increases its resilience against these kind of attacks.

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  • Microsoft Patch Tuesday – May 2018

    - May 8, 2018 - 0 Comments

    Today, Microsoft has released its monthly set of security advisories for vulnerabilities that have been identified and addressed in various products. This month’s advisory release addresses 67 new vulnerabilities, with 21 of them rated critical, 42 of them rated important, and four rated as low severity. These vulnerabilities impact Outlook, Office, Exchange, Edge, Internet Explorer and more.

    In addition to the 67 vulnerabilities referenced above, Microsoft has also released a critical update advisory, ADV180008, which addresses the vulnerability CVE-2018-4944 described in the Adobe security bulletin APSB18-16.

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