This post was authored by Earl Carter & Jaeson Schultz.
Talos is always fascinated by the endless creativity of those who send spam. Miscreants who automate sending spam using botnets are of particular interest. Talos has been tracking a spam botnet that over the past several months that has been spamming weight loss products, male erectile dysfunction medication, and dating/casual sex websites. These are all typical products one would expect to be purveyed through spam. What interests us about this spam are some of the ways the spam is constructed to try and evade detection (a.k.a. spam filters).
Beginning in March, Talos noted an absolute explosion in the usage of link shortening services in spam. After looking into the cause we found botnet ‘unknown2250’, as it is called by the Composite Block List (CBL), to be one of the primary parties responsible for this massive increase.
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Tags: spam, Talos, Threat Research
Adversaries are committed to continually refining or developing new techniques to conceal malicious activity, decrease their reliance on other techniques that may be more detectable, and become increasingly more efficient and effective in their attacks. Below are just three examples—explored in detail in the newly released Cisco 2015 Annual Security Report—of how malicious actors met these goals in 2014. These trends were observed by Cisco Talos Security Intelligence and Research Group throughout last year, and analyzed by the team using a global set of telemetry data:
- Use of malvertising to help deliver exploit kits more efficiently—Talos noted three exploit kits we observed “in the wild” more than others in 2014: Angler, Goon, and Sweet Orange. More than likely, their popularity is due to their technical sophistication in terms of their ability to evade detection and remain effective. The Sweet Orange kit, for example, is very dynamic. Its components are always changing. Adversaries who use Sweet Orange often rely on malvertising to redirect users (often twice) to websites that host the exploit kit, including legitimate websites.
- Increase in Silverlight exploitation—As we reported in both the Cisco 2014 Midyear Security Report and the Cisco 2015 Annual Security Report, the number of exploit kits able to exploit Microsoft Silverlight is growing. While still very low in number compared to more established vectors like Flash, PDF, and Java, Silverlight attacks are on the rise. This is another example of adversaries exploring new avenues for compromise in order to remain efficient and effective in launching their attacks. The Angler and Goon exploit kits both include Silverlight vulnerabilities. Fiesta is another known exploit kit that delivers malware through Silverlight, which our team reported on last year.
- The rise of “snowshoe spam”—Phishing remains an essential tool for adversaries to deliver malware and steal users’ credentials. These actors understand that it is more efficient to exploit users at the browser and email level, rather than taking the time and effort to attempt to compromise servers. To ensure their spam campaigns are effective, Talos observed spammers turning to a new tactic last year: snowshoe spam. Unsolicited bulk email is sent using a large number of IP addresses and at a low message volume per IP address; this prevents some spam systems from detecting the spam, helping to ensure it reaches its intended audience. There is also evidence that adversaries are relying on compromised users’ machines as a way to support their snowshoe spam campaigns more efficiently. Snowshoe spam contributed to the overall increase of spam volume by 250 percent in 2014.
These are only a few of the threat intelligence findings presented in the Cisco 2015 Annual Security Report. We encourage you to read the whole report, but also, to stay apprised of security trends throughout the year by following our reports on the Cisco Security blog. Talos is committed to ongoing coverage of security threats and trends. In fact, in the Cisco 2015 Annual Security Report, you’ll find links to several posts that our researchers published throughout 2014, and were used to help shape and inform our threat intelligence coverage in the report.
Tags: Cisco Annual Security Report 2015, malvertising, security, Silverlight, spam, Talos
The Cisco 2015 Annual Security Report highlights many creative techniques that attackers are exploiting to conceal malicious activity, often taking advantage of gaps in security programs. They are continually refining and developing new techniques to gain a foothold in environments and, increasingly, they are relying on users and IT teams as enablers of attacks to persistently infect and hide in plain sight on machines.
Given this complex and dynamic threat landscape, organizations need a mature and adaptable incident response process.
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Tags: 2015 annual security report, incident response, malware, network infiltration, spam
This post was authored by Armin Pelkmann and Earl Carter.
Talos Security Intelligence and Research Group noticed a reappearance of several Dridex email campaigns, starting last week and continuing into this week as well. Dridex is in a nutshell, malware designed to steal your financial account information. The attack attempts to get the user to install the malicious software on their system through an until lately, rarely exploited attack vector: Microsoft Office Macros. Recently, we noticed a resurgence of macro abuse. If macros are not enabled, social engineering techniques are utilized to try to get the user to enable them. Once the malware is installed on the system, it is designed to steal your online banking credentials when you access your banking site from an infected system.
Talos analyzed three separate campaigns in the last days, all distinguishable from their subject lines. Read More »
Tags: Dridex, Excel, financial, malware, Microsoft, security, spam, Talos, Word
SpamCop is a free, community-based spam email reporting service provided by Cisco. SpamCop analyzes reported spam, and extracts details about the sending IP, the URLs contained in the spam, and the networks over which the spam message has transited. This information is used to create the SpamCop Block List (SCBL). The SCBL a list of IP addresses believed to be sending Unsolicited Bulk Email.
As part of its service, each week SpamCop sends millions of email messages to notify network administrators about malicious activity that is observed occurring on their networks. SpamCop receives all types of replies in response to our notification emails. Many times recipients of SpamCop’s notifications will reply to SpamCop and claim, “we did not send the spam”. The SpamCop Deputies responsible for following up on these replies have heard every excuse under the sun. For them, “we did not send the spam” is the spam block list equivalent of “the dog ate my homework.”
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Tags: hijack, security, spam, Talos