Malware Analysis Report

2025-05-05 22:14

Sample ID 250416-xb94matzb1
Target linux_386.elf
SHA256 5aa6cc2b09d7fa0d3c5b6826f872826f5d3afb9af18c001ea3f4f1a1ccb188f7
Tags
kaiji defense_evasion discovery execution persistence privilege_escalation
score
10/10

Table of Contents

Analysis Overview

MITRE ATT&CK

Enterprise Matrix V16

Analysis: static1

Detonation Overview

Signatures

Analysis: behavioral1

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis Overview

score
10/10

SHA256

5aa6cc2b09d7fa0d3c5b6826f872826f5d3afb9af18c001ea3f4f1a1ccb188f7

Threat Level: Known bad

The file linux_386.elf was found to be: Known bad.

Malicious Activity Summary

kaiji defense_evasion discovery execution persistence privilege_escalation

Kaiji family

Kaiji

Executes dropped EXE

Modifies Watchdog functionality

Enumerates running processes

Modifies init.d

Creates/modifies Cron job

Creates/modifies environment variables

Modifies systemd

Write file to user bin folder

Modifies Bash startup script

Changes its process name

Reads runtime system information

Enumerates kernel/hardware configuration

MITRE ATT&CK

Analysis: static1

Detonation Overview

Reported

2025-04-16 18:41

Signatures

Kaiji

Description Indicator Process Target
N/A N/A N/A N/A

Kaiji family

kaiji

Analysis: behavioral1

Detonation Overview

Submitted

2025-04-16 18:41

Reported

2025-04-16 18:44

Platform

ubuntu2204-amd64-20250410-en

Max time kernel

148s

Max time network

146s

Command Line

[/tmp/linux_386.elf ]

Signatures

Kaiji

Description Indicator Process Target
N/A N/A N/A N/A

Kaiji family

kaiji

Executes dropped EXE

Description Indicator Process Target
N/A /etc/32676 /tmp/linux_386.elf N/A

Modifies Watchdog functionality

defense_evasion
Description Indicator Process Target
File opened for modification /dev/misc/watchdog /tmp/linux_386.elf N/A
File opened for modification /dev/watchdog /tmp/linux_386.elf N/A

Creates/modifies Cron job

execution persistence privilege_escalation
Description Indicator Process Target
File opened for modification /etc/crontab /tmp/linux_386.elf N/A

Creates/modifies environment variables

persistence privilege_escalation defense_evasion
Description Indicator Process Target
File opened for modification /etc/profile.d/bash_cfg /tmp/linux_386.elf N/A
File opened for modification /etc/profile.d/bash_cfg.sh /tmp/linux_386.elf N/A
File opened for modification /etc/profile.d/gateway.sh /tmp/linux_386.elf N/A

Enumerates running processes

Modifies init.d

persistence
Description Indicator Process Target
File opened for modification /etc/init.d/avahi-daemon /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/cups-browsed /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/kmod /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/x11-common /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/alsa-utils /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/cups /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/gdm3 /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/lvm2-lvmpolld /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/plymouth /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/procps /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/apparmor /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/cron /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/cryptdisks /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/hwclock.sh /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/keyboard-setup.sh /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/ssh /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/sssd /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/unattended-upgrades /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/console-setup.sh /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/rsync /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/apport /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/cryptdisks-early /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/dbus /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/openvpn /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/saned /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/spice-vdagent /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/anacron /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/bluetooth /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/iscsid /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/udev /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/acpid /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/open-iscsi /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/plymouth-log /tmp/linux_386.elf N/A

Modifies systemd

persistence privilege_escalation
Description Indicator Process Target
File opened for modification /usr/lib/systemd/system/quotaoff.service /tmp/linux_386.elf N/A

Write file to user bin folder

persistence
Description Indicator Process Target
File opened for modification /usr/bin/include/ps /tmp/linux_386.elf N/A
File opened for modification /usr/bin/include/ls /tmp/linux_386.elf N/A
File opened for modification /usr/bin/include/find /tmp/linux_386.elf N/A
File opened for modification /usr/bin/include/lsof /tmp/linux_386.elf N/A
File opened for modification /usr/bin/ps /tmp/linux_386.elf N/A
File opened for modification /usr/bin/ss /tmp/linux_386.elf N/A
File opened for modification /usr/bin/ls /tmp/linux_386.elf N/A
File opened for modification /usr/bin/include/ss /tmp/linux_386.elf N/A
File opened for modification /usr/bin/include/dir /tmp/linux_386.elf N/A
File opened for modification /usr/bin/dir /tmp/linux_386.elf N/A
File opened for modification /usr/bin/find /tmp/linux_386.elf N/A
File opened for modification /usr/bin/lsof /tmp/linux_386.elf N/A

Modifies Bash startup script

persistence
Description Indicator Process Target
File opened for modification /etc/profile.d/bash_cfg /tmp/linux_386.elf N/A
File opened for modification /etc/profile.d/bash_cfg.sh /tmp/linux_386.elf N/A
File opened for modification /etc/profile.d/gateway.sh /tmp/linux_386.elf N/A

Changes its process name

Description Indicator Process Target
Changes the process name, possibly in an attempt to hide itself ksoftirqd/0 /tmp/linux_386.elf N/A

Enumerates kernel/hardware configuration

discovery
Description Indicator Process Target
File opened for reading /sys/kernel/mm/transparent_hugepage/hpage_pmd_size /tmp/linux_386.elf N/A
File opened for reading /sys/kernel/mm/transparent_hugepage/hpage_pmd_size N/A N/A

Reads runtime system information

discovery
Description Indicator Process Target
File opened for reading /proc/1243/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1356/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1567/stat /tmp/linux_386.elf N/A
File opened for reading /proc/filesystems /usr/bin/systemctl N/A
File opened for reading /proc/732/stat /tmp/linux_386.elf N/A
File opened for reading /proc/736/stat /tmp/linux_386.elf N/A
File opened for reading /proc/783/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1032/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1105/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1181/stat /tmp/linux_386.elf N/A
File opened for reading /proc/896/stat /tmp/linux_386.elf N/A
File opened for reading /proc/927/stat /tmp/linux_386.elf N/A
File opened for reading /proc/988/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1012/stat /tmp/linux_386.elf N/A
File opened for reading /proc/589/stat /tmp/linux_386.elf N/A
File opened for reading /proc/926/stat /tmp/linux_386.elf N/A
File opened for reading /proc/979/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1110/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1196/stat /tmp/linux_386.elf N/A
File opened for reading /proc/filesystems /usr/bin/sed N/A
File opened for reading /proc/filesystems /usr/bin/systemctl N/A
File opened for reading /proc/890/stat /tmp/linux_386.elf N/A
File opened for reading /proc/989/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1085/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1103/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1312/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1115/stat /tmp/linux_386.elf N/A
File opened for reading /proc/418/stat /tmp/linux_386.elf N/A
File opened for reading /proc/594/stat /tmp/linux_386.elf N/A
File opened for reading /proc/907/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1119/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1344/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1520/stat /tmp/linux_386.elf N/A
File opened for reading /proc/427/stat /tmp/linux_386.elf N/A
File opened for reading /proc/559/stat /tmp/linux_386.elf N/A
File opened for reading /proc/649/stat /tmp/linux_386.elf N/A
File opened for reading /proc/997/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1125/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1324/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1449/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1574/stat /tmp/linux_386.elf N/A
File opened for reading /proc/314/stat /tmp/linux_386.elf N/A
File opened for reading /proc/799/stat /tmp/linux_386.elf N/A
File opened for reading /proc/973/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1025/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1111/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1580/stat /tmp/linux_386.elf N/A
File opened for reading /proc/407/stat /tmp/linux_386.elf N/A
File opened for reading /proc/552/stat /tmp/linux_386.elf N/A
File opened for reading /proc/590/stat /tmp/linux_386.elf N/A
File opened for reading /proc/668/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1104/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1109/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1436/stat /tmp/linux_386.elf N/A
File opened for reading /proc/filesystems /usr/bin/journalctl N/A
File opened for reading /proc/741/stat /tmp/linux_386.elf N/A
File opened for reading /proc/769/stat /tmp/linux_386.elf N/A
File opened for reading /proc/315/stat /tmp/linux_386.elf N/A
File opened for reading /proc/filesystems /usr/bin/sed N/A
File opened for reading /proc/699/stat /tmp/linux_386.elf N/A
File opened for reading /proc/760/stat /tmp/linux_386.elf N/A
File opened for reading /proc/948/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1551/stat /tmp/linux_386.elf N/A
File opened for reading /proc/775/stat /tmp/linux_386.elf N/A

Processes

/tmp/linux_386.elf

[/tmp/linux_386.elf ]

/etc/32676

[/etc/32676]

/usr/bin/basename

[basename /usr/sbin/service]

/usr/bin/sleep

[sleep 60]

/usr/bin/basename

[basename /usr/sbin/service]

/usr/bin/sed

[sed -ne s/\.socket\s*[a-z]*\s*$/.socket/p]

/usr/bin/systemctl

[systemctl list-unit-files --full --type=socket]

/usr/local/sbin/systemctl

[systemctl start crond.service]

/usr/local/bin/systemctl

[systemctl start crond.service]

/usr/sbin/systemctl

[systemctl start crond.service]

/usr/bin/systemctl

[systemctl start crond.service]

/usr/bin/systemctl

[systemctl daemon-reload]

/usr/bin/systemctl

[systemctl enable quotaoff.service]

/usr/bin/systemctl

[systemctl start quotaoff.service]

/usr/bin/journalctl

[journalctl -xe --no-pager]

/usr/bin/basename

[basename /usr/sbin/service]

/usr/bin/basename

[basename /usr/sbin/service]

/usr/bin/sed

[sed -ne s/\.socket\s*[a-z]*\s*$/.socket/p]

/usr/bin/systemctl

[systemctl list-unit-files --full --type=socket]

/usr/local/sbin/systemctl

[systemctl start cron.service]

/usr/local/bin/systemctl

[systemctl start cron.service]

/usr/sbin/systemctl

[systemctl start cron.service]

/usr/bin/systemctl

[systemctl start cron.service]

/usr/bin/sleep

[sleep 60]

/usr/bin/sleep

[sleep 60]

Network

Country Destination Domain Proto
N/A 224.0.0.251:5353 udp
US 8.8.8.8:53 www.google.com udp
US 8.8.8.8:53 www.google.com udp
US 154.40.47.248:888 tcp

Files

/etc/.walk

MD5 be61c2bc8a19feeea95e41d0e94962fd
SHA1 b6c8e9a0a0cbf3e798f1e6669508bc7e9ad43173
SHA256 edb1c48d5c2a89d9e1a570967cf2dff861485814636c1c4a26bf4ee6dbe402e1
SHA512 e229c10ac49bf73a846ed9a58fa4fdb6e49a8cc07209094b92a2bf9bc6b72954c68c129800e4c356a7c7b383a8a5fe70d0401eafa8cb1382142778303179c6ac

/etc/.walk

MD5 7fb437af67907135c8eb965295be8ea2
SHA1 325692899cabcbb1fbf3ecb751f53ca78db88436
SHA256 69b3cbc38cafc06e2a36e10cec346941953745563e2239d6284bd38bb0b1b5e7
SHA512 c7eb8050562741c375a13b1076dc6e2cbb3533541f33222b09db0a9bd8cd02b8a1932566d53e5b2822d6b21feb2cf94ba0695b7bd9d6902874b1acfacf3ff2a8

/etc/32676

MD5 585f408444cbca746945f0cb63f2c3f0
SHA1 0e44bae17174f04514e770ca7fc4bec1007e39cd
SHA256 ebb961c647363dfa90f302de378e0e61807b9b792fc86616635a713cca8f4299
SHA512 022241dbafad55164701f67ef5b84154e3af97c5dfe77dee7bf8406f2befbd2962bbf4f243432b2f41d6c2376b87fcf551fd6945e03ddb02a5619c2f0f69c596

/boot/System.mod

MD5 259800bf6d1eb21a74ff1737f9826a0a
SHA1 1a13ffb1f327ae411689568840b0e812b7d40a59
SHA256 5aa6cc2b09d7fa0d3c5b6826f872826f5d3afb9af18c001ea3f4f1a1ccb188f7
SHA512 d3b013396695920dde44c4bc8af2b91e9e4142592151056e27946af54096056f2a70d528c4fd9abb27042d6a5ed2839648fbe3054b3e8a218bf29586237c1beb

/usr/lib/systemd/system/quotaoff.service

MD5 b02de6cd28cd922b18d9d93375a70d8b
SHA1 021426a5a2ff9edc80ba5936c94b37525538885e
SHA256 d8d8e5cd33aa3450cd74c63716a02f3dff39efef2836559f110bc93663b1380a
SHA512 db3fe03ad5e599e6c03aaec7bf1242f5509fbb624adb9afb7499e25487daef3f3f1c6babf51570b527a5ac5c9f4b079ae4cc53baa9497c0a121328bef8d04422

/.mod

MD5 f5a3713282e43c200f30342f5ff5e2ea
SHA1 2b2ce1a207e2b691a074c6f78f71c4785aae426a
SHA256 6ab64e727571458d4884fb2fe82c27c467db0699cb8f648b3f0217c35d2b7511
SHA512 5bcb8cd360409147a486755f90e0cdd97183af02ce8de5135b7c6a8a010deb9ef12dcd5ee9a2a8fd2e159347f68e72d6b7fd75e943b4fcd928d7a74b97476013

/etc/profile.d/gateway.sh

MD5 f2b1f3db600ea068846bf5937f3f0ea4
SHA1 ec98496f6cfbd295a9679a912f3d75a72e1183fe
SHA256 bd6a2dbd29257d09768bc45cbbd3a75fbafe26f49f8d1487ac35644cb7a53e47
SHA512 7cc944508882ea9bf98c7f6e7d86394410fc273643430422d267595d498a919999e5ca939d90f4fdc81a69201b83cd1a687a7ffa9f4f671799fb5a0a6ea294be