Jaeson Schultz

5 min read

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 […]

5 min read

This blog post was authored by Martin Lee and Jaeson Schultz. With the announcement that yet another major retailer has allegedly been breached, it is important to review how attackers compromise retail systems and how such intrusions can be prevented. In this latest case, retailers are working to determine if a large cache of credit […]

4 min read

This blog was co-authored by Kevin Brooks, Alex Chiu, Joel Esler, Martin Lee, Emmanuel Tacheau, Andrew Tsonchev, and Craig Williams.   On the 21st of July, 2014, Cisco TRAC became aware that the website dwnews.com was serving malicious Adobe Flash content. This site is a Chinese language news website covering events in East Asia from a […]

3 min read

It is not uncommon to see an anti-spam system catch >99% of the spam passing through it. Most of the best anti-spam systems catch >99.9% of spam. In this environment, spammers try just about anything to evade spam filters. Some spammers believe that blasting at high volume is the key to success. Others believe complete […]

2 min read

Takedowns of prolific spam botnets, such as Rustock in 2011 and Grum in 2012, had a substantial effect on reducing overall global spam volumes. This, combined with diminishing returns for spammers sending via bots, had left many email recipients basking in the comfort of (mostly) clean inboxes. No doubt this downward trend in global spam […]

2 min read

On January 16, 2014, Proofpoint discussed a spam attack conducted via “smart devices which have been compromised.” Among the devices cited by Proofpoint as participating in the “Thingbot” were routers, set-top boxes, game consoles, and purportedly, even one refrigerator. Of course, news about a refrigerator sending spam generates considerable media attention, as it should, since […]

3 min read

In October 2013, Cisco TRAC discussed Network Time Protocol (NTP) as a possible vector for amplified distributed denial of service (DDoS) attacks. Litnet CERT has since revealed that their NTP servers were used in a denial of service (DoS) attack. Symantec also published information regarding an NTP amplification-based DDoS attack that occurred in December 2013. On December 7, 2013, a hackforums.net user posted an NTP amplification DDoS script to Pastebin. The NTP DDoS script is heavily obfuscated Perl, though the plain text at the top credits the "leaking" of the script to an individual who goes by the handle Starfall. Brian Krebs also mentioned someone going by the name Starfall as a paying user of booter.tw. They may be the same person.

3 min read

When Fox-IT published their report regarding malvertisements coming from Yahoo, they estimated the attack began on December 30, 2013, while also noting that other reports indicated the attack may have begun earlier. Meanwhile, Yahoo intimated a different timeframe for the attack, claiming “From December 31 to January 3 on our European sites, we served some […]

4 min read

On October 22, 2013, Cisco TRAC Threat Researcher Martin Lee wrote about Distributed Denial of Service (DDoS) attacks that leverage the Domain Name System (DNS) application protocol. As Martin stated, the wide availability of DNS open resolvers combined with attackers’ ability to falsify the source of User Datagram Protocol (UDP) packets creates a persistent threat […]