During the second quarter of 2018, the United States has become the top region by number of distributed denial of service (DDoS) botnet command and control (C&C) servers, accounting for nearly half of them, Kaspersky Lab reports.
Of all known C&C centers worldwide, 44.75% are located in the U.S., up from 29.32% during the first three months of the year. South Korea lost nearly 20 percentage points from the first quarter and ended Q2 on the second position, at 11.05%. Italy (6.83%), China (5.52%), and France (3.31%) round up top 5.
Another significant change observed during this quarter was a massive increase in the number of DDoS attacks from Linux botnets, which reached 94.47% of all single-family attacks, compared to 66.49% in Q1.
The swing is mainly due to a multifold drop in the activity of the Yoyo Windows botnet, paired with a decrease in the activity of Nitol, Drive, and Skill. Simultaneously, “Xor for Linux significantly increased its number of attacks,” Kaspersky reports.
China continues to lead by number of attacks with a 59.03% share, followed by Hong Kong at 17.13%, and the United States at 12.46%. During the quarter, the top 10 countries accounted for 96.44% of the attacks.
According to Kaspersky, which only counted DDoS attacks originating from botnets, China also accounted for the largest share of unique targets (52.36%), followed by the U.S. (17.5%) and Hong Kong (12.88%).
The longest attack observed during the three-month period lasted 258 hours (almost 11 days), being only slightly shorter compared to the longest attack in Q1, which lasted for 297 hours (12.4 days). The number of short attacks (up to 4 hours) dropped significantly in the quarter.
“The share of SYN attacks rose sharply to 80.2%; second place went to UDP attacks with 10.6%,” Kaspersky reveals.
The security firm also noticed that the average and maximum attack power of decreased slightly compared to the second half of last year, but they remained high above the levels observed in the first half of 2017, presumably because of third-party amplification.
Attackers are looking for non-standard amplification methods to increase the power of their attacks, as the recent wave of Memcached-based attacks has proved. Known since 2001, a vulnerability in the Universal Plug and Play protocol has been leveraged for amplification and obfuscation of source ports, thus bypassing existing defenses.
Some of the most significant attacks observed in the quarter include the assault on encrypted email provider ProtonMail and the charge on Mexican elections. Another important event during the timeframe, however, was the shutdown of Webstresser.org, the largest DDoS services marketplace.
Source: infosec island