Tag Archives: botnet

Malware Hunter: Find C&C servers for botnets

Recorded Future and Shodan released Malware Hunter, a specialized crawler for security researchers that explores the Internet to find computers acting as remote access trojan (RAT) command and control centers. What Malware Hunter does Malware Hunter unearths computers hosting RAT controller software that remotely controls malware-infected computers and instructs them to execute malicious activities such as recording audio, video, and keystrokes on a victim’s machine. Using command and control servers, attackers can launch widescale attacks … More ?

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Malware Hunter: Find C&C servers for botnets

Locky ransomware makes a comeback, courtesy of Necurs botnet

The Necurs botnet has, once again, begun pushing Locky ransomware on unsuspecting victims. The botnet, which flip-flops from sending penny stock pump-and-dump emails to booby-trapped files that lead to malware (usually Locky or Dridex), has been spotted slinging thousand upon thousand of emails in the last three or four days. “Talos has seen in excess of 35K emails in the last several hours associated with this newest wave of Locky,” Cisco Talos researchers noted on … More ?

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Locky ransomware makes a comeback, courtesy of Necurs botnet

Hajime IoT worm infects devices to head off Mirai

Mirai is the name of the worm that has taken control of many IoT devices around the world and used them to mount DDoS attacks, the most high-profile of which was directed against US-based DNS provider Dyn and resulted in many websites and online services being inaccessible for hours on end. Its source code was leaked by the author, which lead to the creation of more botnets, and an increased fear that we’ll soon witness … More ?

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Hajime IoT worm infects devices to head off Mirai

IoT devices under attack: Amnesia hijacks, BrickerBot destroys

Every hour of every day, computer systems and IoT devices are under attack by bots trying to recruit them into growing botnets. Security researchers have recently highlighted two of these threats coming after Linux- and BusyBox-based systems and devices. Amnesia A year after security researcher Rotem Kerner discovered a remote code execution vulnerability that affected digital video recorders (DVRs) manufactured by Chinese company TVT Digital and sold by more than 70 different vendors around the … More ?

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IoT devices under attack: Amnesia hijacks, BrickerBot destroys

20,000-bots-strong Sathurbot botnet grows by compromising WordPress sites

A 20,000-bots-strong botnet is probing WordPress sites, trying to compromise them and spread a backdoor downloader Trojan called Sathurbot as far and as wide as possible. Sathurbot: A versatile threat “Sathurbot can update itself and download and start other executables. We have seen variations of Boaxxe, Kovter and Fleercivet, but that is not necessarily an exhaustive list,” the researchers noted. Sathurbot is also a web crawler, and searches for domain names that can be probed … More ?

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20,000-bots-strong Sathurbot botnet grows by compromising WordPress sites

Bigger than Mirai: Leet Botnet delivers 650 Gbps DDoS attack with ‘pulverized system files’

Earlier in the year, a huge DDoS attack was launched on Krebs on Security. Analysis showed that the attack pelted servers with 620 Gbps, and there were fears that the release of the Mirai source code used to launch the assault would lead to a rise in large-scale DDoS attacks. Welcome Leet Botnet. In the run-up to Christmas, security firm Imperva managed to fend off a 650 Gbps DDoS attack. But this was nothing to do with Mirai; it is a completely new form of malware, but is described as “just as powerful as the most dangerous one to date”. The concern for 2017 is that “it’s about to get a lot worse”. Clearly proud of the work put into the malware, the creator or creators saw fit to sign it. Analysis of the attack showed that the TCP Options header of the SYN packets used spelled out l33t, hence the Leet Botnet name. The attack itself took place on 21 December, but details of what happened are only just starting to come out. It targeted a number of IP addresses, and Imperva speculates that a single customer was not targeted because of an inability to resolve specific IP addresses due to the company’s proxies. One wave of the attack generated 650 Gbps of traffic — or more than 150 million packets per second. Despite attempting to analyze the attack, Imperva has been unable to determine where it originated from, but the company notes that it used a combination of both small and large payloads to “clog network pipes  and  bring down network switches”. While the Mirai attacks worked by firing randomly generated strings of characters to generate traffic, in the case of Leet Botnet the malware was accessing local files and using scrambled versions of the compromised content as its payload. Imperva describes the attack as “a mishmash of pulverized system files from thousands upon thousands of compromised devices”. What’s the reason for using this particular method? Besides painting a cool mental image, this attack method serves a practical purpose. Specifically, it makes for an effective obfuscation technique that can be used to produce an unlimited number of extremely randomized payloads. Using these payloads, an offender can circumvent signature-based security systems that mitigate attacks by identifying similarities in the content of network packets. While in this instance Imperva was able to mitigate the attack, the company says that Leet Botnet is “a sign of things to come”. Brace yourself for a messy 2017… Source: http://betanews.com/2016/12/28/leet-botnet-ddos/

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Bigger than Mirai: Leet Botnet delivers 650 Gbps DDoS attack with ‘pulverized system files’

New botnet launching daily massive DDoS attacks

CloudFlare spotted a new botnet in the wild which launched massive DDoS attacks aimed at the US West Coast for 10 days in a row. A new monster botnet, which hasn’t been given a name yet, has been spotted in the wild launching massive DDoS attacks. Security experts at CloudFlare said the emerging botnet is not related to Mirai, but it is capable of enormous distributed denial-of-service attacks. If this new botnet is just starting up, it could eventually be as powerful as Mirai. The company has so far spent 10 days fending off DDoS attacks aimed at targets on the US West Coast; the strongest attacks peaked at over 480 gigabits per second (Gbps) and 200 million packets per second (Mpps). CloudFlare first detected the new botnet on November 23; peaking at 400 Gbps and 172 Mpps, the DDoS attack hammered on targets “non-stop for almost exactly 8.5 hours” before the attack ended. CloudFlare’s John Graham-Cumming noted, “It felt as if an attacker ‘worked’ a day and then went home.” The botnet DDoS attacks followed the same pattern the next day, like the attacker was “someone working at a desk job,” except the attacks began 30 minutes earlier. On the third day, the attacks reached over 480 Gbps and 200 Mpps before the attacker decided to knock off a bit early from ‘work.’ Once Thanksgiving, Black Friday and Cyber Monday were over, the attacker changed patterns and started working 24 hours a day. The attacks continued for 10 days; each day the DDoS attacks “were peaking at 400 Gbps and hitting 320 Gbps for hours on end.” That’s not as powerful as the Mirai botnet made up of insecure IoT devices, but this botnet is presumably just getting started. It’s already plenty big enough to bring a site to its knees for hours on end unless it has some decent form of DDoS protection. If it were to be combined with other botnet strains, it might be capable of beating the unprecedented records set by the Mirai attacks. Although CloudFlare never elaborated on what devices the new botnet was abusing for its attacks, the company said it uses different attack software then Mirai. The emerging botnet sends very large Layer 3 and Layer 4 floods aimed at the TCP protocol. Hopefully it’s not using poorly secured internet of things devices as there seems to be an endless supply of IoT devices with pitiful-to-no security waiting to be added to botnets. That’s likely going to get worse, since IoT gadgets are expected to sell in record-breaking numbers this holiday season. It’s just a guess, but it does seem likely that the new botnet is aimed at such devices. CloudFlare posted the new botnet information on Friday, so it is unknown if the attacks have continued since the article was published. Last week, a modified version of the Mirai IoT malware was responsible for creating chaos in Germany and other worldwide locations; the hackers reportedly responsible for attempting to add routers to their botnet apologized for knocking Deutsche Telekom customers offline as it was allegedly not their intention. DDoS attacks may give a blue Christmas to gamers Regarding DDoS attacks, the most recent Akamai State of the Internet/Security Report suggested that gamers might not have the best holiday season. For the past several years, hackers have attacked and sometimes taken down Microsoft’s Xbox and Sony’s PlayStation networks, even Steam, making it impossible for seasoned gamers as well as those who received new gaming platforms for Christmas to enjoy new games and consoles. “Thanksgiving, Christmas, and the holiday season in general have long been characterized by a rise in the threat of DDoS attacks,” the Akamai report stated. “Malicious actors have new tools – IoT botnets – that will almost certainly be used in the coming quarter.” As first pointed out by Network World’s Tim Greene, Akamai added, “It is very likely that malicious actors are now working diligently to understand how they can capture their own huge botnet of IoT devices to create the next largest DDoS ever.” Let’s hope the newly discovered botnet isn’t an example of Akamai’s prediction. Source:http://www.computerworld.com/article/3147081/security/new-botnet-launching-daily-massive-ddos-attacks.html

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New botnet launching daily massive DDoS attacks

New Mirai Worm Knocks 900K Germans Offline

More than 900,000 customers of German ISP  Deutsche Telekom  (DT) were knocked offline this week after their Internet routers got infected by a new variant of a computer worm known as  Mirai.  The malware wriggled inside the routers via a newly discovered vulnerability in a feature that allows ISPs to remotely upgrade the firmware on the devices. But the new Mirai malware turns that feature off once it infests a device, complicating DT’s cleanup and restoration efforts. Security experts say the multi-day outage is a sign of things to come as cyber criminals continue to aggressively scour the Internet of Things (IoT) for vulnerable and poorly-secured routers, Internet-connected cameras and digital video recorders (DVRs). Once enslaved, the IoT devices can be used and rented out for a variety of purposes — from conducting massive denial-of-service attacks capable of knocking large Web sites offline to helping cybercriminals stay anonymous online. This new variant of Mirai builds on malware source code released at the end of September. That leak came a little more a week after a botnet based on Mirai was used in a record-sized attack that caused KrebsOnSecurity to go offline for several days. Since then, dozens of new Mirai botnets have emerged, all competing for a finite pool of vulnerable IoT systems that can be infected. Until this week, all Mirai botnets scanned for the same 60+ factory default usernames and passwords used by millions of IoT devices. But the criminals behind one of the larger Mirai botnets apparently decided to add a new weapon to their arsenal, incorporating exploit code published earlier this month for a security flaw in specific routers made by Zyxel and Speedport. These companies act as original equipment manufacturers (OEMs) that specialize in building DSL modems that ISPs then ship to customers. The vulnerability exists in communications protocols supported by the devices that ISPs can use to remotely manage all of the customer-premises routers on their network. According to BadCyber.com, which first blogged about the emergence of the new Mirai variant, part of the problem is that Deutsche Telekom does not appear to have followed the best practice of blocking the rest of the world from remotely managing these devices as well. “The malware itself is really friendly as it closes the vulnerability once the router is infected,” BadCyber noted. “It performs [a] command which should make the device ‘secure,’ until next reboot. The first one closes port 7547 and the second one kills the telnet service, making it really hard for the ISP to update the device remotely.” [For the Geek Factor 5 readership out there, the flaw stems from the way these routers parse incoming traffic destined for Port 7547using communications protocols known as TR-069]. DT has been urging customers who are having trouble to briefly disconnect and then reconnect the routers, a process which wipes the malware from the device’s memory. The devices should then be able to receive a new update from DT that plugs the vulnerability. That is, unless the new Mirai strain gets to them first.  Johannes Ullrich , dean of security research at  The SANS Technology Institute , said this version of Mirai aggressively scans the Internet for new victims, and that SANS’s research has shown vulnerable devices are compromised by the new Mirai variant within five to ten minutes of being plugged into the Internet. Ullrich said the scanning activity conducted by the new Mirai variant is so aggressive that it can create hangups and crashes even for routers that are are not vulnerable to this exploit. “Some of these devices went down because of the sheer number of incoming connections” from the new Mirai variant, Ullrich said. “They were listening on Port 7547 but were not vulnerable to this exploit and were still overloaded with the number of connections to that port.” FEEDING THE CRIME MACHINE Allison Nixon , director of security research at Flashpoint, said this latest Mirai variant appears to be an attempt to feed fresh victims into one of the larger and more established Mirai botnets out there today. Nixon said she suspects this particular botnet is being rented out in discrete chunks to other cybercriminals. Her suspicions are based in part on the fact that the malware phones home to a range of some 256 Internet addresses that for months someone has purchased for the sole purpose of hosting nothing but servers used to control multiple Mirai botnets. “The malware points to some [Internet addresses] that are in ranges which were purchased for the express purpose of running Mirai,” Nixon said. “That range does nothing but run Mirai control servers on it, and they’ve been doing it for a while now. I would say this is probably part of a commercial service because purchasing this much infrastructure is not cheap. And you generally don’t see people doing this for kicks, you see them doing it for money.” Nixon said the criminals behind this new Mirai variant are busy subdividing their botnet — thought to be composed of several hundred thousand hacked IoT devices — among multiple, distinct control servers. This approach, she said, addresses two major concerns among cybercriminals who specialize in building botnets that are resold for use in huge distributed denial of service (DDoS) attacks. The first is that extended DDoS attacks which leverage firepower from more bots than are necessary to take down a target host can cause the crime machine’s overall bot count to dwindle more quickly than the botnet can replenish itself with newly infected IoT devices — greatly diminishing the crime machine’s strength and earning power. “I’ve been watching a lot of chatter in the DDoS community, and one of the topics that frequently comes up is that there are many botnets out there where the people running them don’t know each other, they’ve just purchased time on the botnet and have been assigned specific slots on it,” Nixon said. “Long attacks would end up causing the malware or infected machines to crash, and the attack and would end up killing the botnet if it was overused. Now it looks like someone has architected a response to that concern, knowing that you have to preserve bots as much as you can and not be excessive with the DDoS traffic you’re pushing.” Nixon said dividing the Mirai botnet into smaller sections which each answer to multiple control servers also makes the overall crime machine more resistant to takedown efforts by security firms and researchers. “This is an interesting development because a lot of the response to Mirai lately has been to find a Mirai controller and take it down,” Nixon said. “Right now, the amount of redundant infrastructure these Mirai actors have is pretty significant, and it suggests they’re trying to make their botnets more difficult to take down.” Nixon said she worries that the aggressive Mirai takedown efforts by the security community may soon prompt the crooks to adopt far more sophisticated and resilient methods of keeping their crime machines online. “We have to realize that the takedown option is not going to be there forever with these IoT botnets,” she said. Source: https://krebsonsecurity.com/2016/11/new-mirai-worm-knocks-900k-germans-offline/

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New Mirai Worm Knocks 900K Germans Offline

Analyzing the latest wave of mega attacks

A new report, using data gathered from the Akamai Intelligent Platform, provides analysis of the current cloud security and threat landscape, including insight into two record?setting DDoS attacks caused by the Mirai botnet. Nineteen DDoS attacks exceeded 100 Gbps, with six exceeding 200 Gbps DDoS attacks The two largest DDoS attacks this quarter, both leveraging the Mirai botnet, were the biggest observed by Akamai to-date – recorded at 623 Gbps and 555 Gbps. Compared to … More ?

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Analyzing the latest wave of mega attacks

Apocalypse now: The IoT DDoS threat

One of the things you learn about humanity, if you’re paying attention, is that “gold rushes” bring out the worse in us. When there are no constraints and there is a greed motivator, people will literally trample anyone or anything to get to the goods. Over the ages, literal and financial empires have been forged on this principle, and no matter when or for what particular gain, there has always been serious collateral damage. Despite … More ?

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Apocalypse now: The IoT DDoS threat