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March 25, 2023Severity Medium Analysis Summary GandCrab – a ransomware-as-a-service variant – was discovered in early 2018. At least five versions of GandCrab have been created since its […]March 25, 2023Severity Medium Analysis Summary NjRat is a Remote Access Trojan, which is found leveraging Pastebin to deliver a second-stage payload after initial infection. There are multiple […]March 24, 2023Severity Medium Analysis Summary CVE-2023-20113 Cisco SD-WAN vManage Software is vulnerable to cross-site request forgery, caused by improper validation of user-supplied input. By persuading an authenticated […]Threat Insights
Before Rewterz got its start, the market was in dire need of a specialized and dedicated information security company. It was nearly impossible for businesses to find a trustworthy provider that could truly cover all of their bases. We wanted to meet this need, giving companies across the globe a chance to get ahead while knowing that their data is in good hands.
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Platform
Managed Security Services
Managed Penetration Testing
Rewterz penetration testing services help organizations determine if a cyber attacker can gain access to their critical assets while giving them detailed insights of the overall business impact of a cyber attack.
Resources
March 25, 2023Severity Medium Analysis Summary GandCrab – a ransomware-as-a-service variant – was discovered in early 2018. At least five versions of GandCrab have been created since its […]March 25, 2023Severity Medium Analysis Summary NjRat is a Remote Access Trojan, which is found leveraging Pastebin to deliver a second-stage payload after initial infection. There are multiple […]March 24, 2023Severity Medium Analysis Summary CVE-2023-20113 Cisco SD-WAN vManage Software is vulnerable to cross-site request forgery, caused by improper validation of user-supplied input. By persuading an authenticated […]Threat Insights
Before Rewterz got its start, the market was in dire need of a specialized and dedicated information security company. It was nearly impossible for businesses to find a trustworthy provider that could truly cover all of their bases. We wanted to meet this need, giving companies across the globe a chance to get ahead while knowing that their data is in good hands.
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Rewterz Threat Advisory -CVE-2018-11803 – Apache Subversion Denial of Service Vulnerability
February 8, 2019Rewterz Threat Alert -Malware Campaign Hides Ransomware in Super Mario Wrapper
February 11, 2019
Severity
Medium
Category
Cyber Crime
Analysis Summary
Linux Platform is being targeted by a new malware strain that installs the XMR-Stak Cryptonight cryptocurrency miner. Additionally, it also searches for other Linux malware and coin miners already present on the compromised machine, and kills them to maximize its own cryptocurrency mining.
This KORKERDS variant downloads the universal Stratum XMR-Stak pool miner which uses the system’s CPU or GPU to mine Cryptonight currencies. Following activities have also been observed:
Function B kills previously installed malware, coin miners, and all related services referenced to an accompanying malware. It also creates new directories, files, and stops processes with connections to identified IP addresses. Function D downloads the coin miner binary from hxxp://yxarsh[.]shop/64 and runs it. Function C downloads a script from hxxp://yxarsh[.]shop/0, saves it to /usr/local/bin/dns file, and creates a new crontab to call this script at 1 a.m. It also downloads hxxp://yxarsh[.]shop/1.jpg and puts it in different crontabs.
The malware will also make sure to clear system logs to erase its traces, and will also achieve persistence avoiding removal after reboots or deletion with the help of the implanted crontab files. The second stage of the infection originates from multiple IP cameras and web services via the TCP port 8161, from domains where the attackers have stored the crontab file which launches the main stage of the malware attack.
Impact
Cryptocurrency mining
Other unspecified impact is also possible
Affected Products
Linux
Indicators of Compromise
URLs
drnfbu[.]xyz:26750
hxxp://yxarsh.shop
hxxp://yxarsh.shop/0
hxxp://yxarsh.shop/1.jpg
hxxp://yxarsh.shop/64
hxxp://yxarsh.shop/86
hxxps://pastebin.com/u/SYSTEAM
Filename
/opt/yilu/mservice
/opt/yilu/work/xig/xig
/opt/yilu/work/xige/xige
/tmp/thisxxs
/usr/bin/.sshd
/usr/bin/bsd-port/getty
/usr/local/bin/dns
/etc/cron.hourly/oanacroner
/etc/cron.daily/oanacroner
/etc/cron.monthly/oanacroner
Erased:
/var/spool/mail/root
/var/log/wtmp
/var/log/secure
/var/log/cron
Malware Hash (MD5/SHA1/SH256)
d9390bbbc6e399a388ac6ed601db4406eeb708f3893a40f88346ee002398955c
2f7ff54b631dd0af3a3d44f9f916dbde5b30cdbd2ad2a5a049bc8f2d38ae2ab6
Remediation
Block the threat indicators at their respective controls.
Keep all Linux systems up-to-date with the latest patches against all vulnerabilities, as Linux is seen to be targeted by many threat actors.