Malware Analysis Report

2025-05-05 22:14

Sample ID 250419-xgc13sszgv
Target linux_386.elf
SHA256 71ccac9d63fd1c2799963f5e5d87ee62f0c306741ae796dc4ea3777bdb0e8f09
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

71ccac9d63fd1c2799963f5e5d87ee62f0c306741ae796dc4ea3777bdb0e8f09

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_chaosbot

Kaiji

Executes dropped EXE

Modifies Watchdog functionality

Modifies init.d

Modifies systemd

Enumerates running processes

Write file to user bin folder

Creates/modifies environment variables

Creates/modifies Cron job

Modifies Bash startup script

Changes its process name

Reads runtime system information

Enumerates kernel/hardware configuration

GoLang User-Agent

MITRE ATT&CK

Analysis: static1

Detonation Overview

Reported

2025-04-19 18:49

Signatures

Kaiji

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

Kaiji family

kaiji

kaiji_chaosbot

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

Analysis: behavioral1

Detonation Overview

Submitted

2025-04-19 18:49

Reported

2025-04-19 18:51

Platform

ubuntu2204-amd64-20250307-en

Max time kernel

149s

Max time network

149s

Command Line

[/etc/32678]

Signatures

Kaiji

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

Kaiji family

kaiji

kaiji_chaosbot

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

Executes dropped EXE

Description Indicator Process Target
N/A /etc/32678 N/A N/A

Modifies Watchdog functionality

defense_evasion
Description Indicator Process Target
File opened for modification /dev/watchdog /tmp/linux_386.elf N/A
File opened for modification /dev/misc/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_config.sh /tmp/linux_386.elf N/A
File opened for modification /etc/profile.d/bash_config /tmp/linux_386.elf N/A
File opened for modification /etc/profile.d/linux.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/linux_kill /tmp/linux_386.elf N/A
File opened for modification /etc/init.d/ssh /tmp/linux_386.elf N/A

Modifies systemd

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

Write file to user bin folder

persistence
Description Indicator Process Target
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/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
File opened for modification /usr/bin/ps /tmp/linux_386.elf N/A

Modifies Bash startup script

persistence
Description Indicator Process Target
File opened for modification /etc/profile.d/bash_config.sh /tmp/linux_386.elf N/A
File opened for modification /etc/profile.d/bash_config /tmp/linux_386.elf N/A
File opened for modification /etc/profile.d/linux.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/643/stat /tmp/linux_386.elf N/A
File opened for reading /proc/786/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1135/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1588/stat /tmp/linux_386.elf N/A
File opened for reading /proc/217/stat /tmp/linux_386.elf N/A
File opened for reading /proc/263/stat /tmp/linux_386.elf N/A
File opened for reading /proc/722/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/1051/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1102/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1787/stat /tmp/linux_386.elf N/A
File opened for reading /proc/205/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1194/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1579/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/640/stat /tmp/linux_386.elf N/A
File opened for reading /proc/742/stat /tmp/linux_386.elf N/A
File opened for reading /proc/767/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1097/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1218/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1752/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/systemctl N/A
File opened for reading /proc/1331/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1704/stat /tmp/linux_386.elf N/A
File opened for reading /proc/636/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1020/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1087/stat /tmp/linux_386.elf N/A
File opened for reading /proc/filesystems /usr/bin/systemctl N/A
File opened for reading /proc/1592/stat /tmp/linux_386.elf N/A
File opened for reading /proc/740/stat /tmp/linux_386.elf N/A
File opened for reading /proc/917/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1137/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1206/stat /tmp/linux_386.elf N/A
File opened for reading /proc/filesystems /usr/bin/systemctl N/A
File opened for reading /proc/610/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1018/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1190/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1583/stat /tmp/linux_386.elf N/A
File opened for reading /proc/635/stat /tmp/linux_386.elf N/A
File opened for reading /proc/781/stat /tmp/linux_386.elf N/A
File opened for reading /proc/925/stat /tmp/linux_386.elf N/A
File opened for reading /proc/990/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1093/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1349/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1575/stat /tmp/linux_386.elf N/A
File opened for reading /proc/413/stat /tmp/linux_386.elf N/A
File opened for reading /proc/415/stat /tmp/linux_386.elf N/A
File opened for reading /proc/762/stat /tmp/linux_386.elf N/A
File opened for reading /proc/981/stat /tmp/linux_386.elf N/A
File opened for reading /proc/filesystems /usr/bin/systemctl N/A
File opened for reading /proc/1223/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1230/stat /tmp/linux_386.elf N/A
File opened for reading /proc/1708/stat /tmp/linux_386.elf N/A
File opened for reading /proc/453/stat /tmp/linux_386.elf N/A
File opened for reading /proc/539/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/797/stat /tmp/linux_386.elf N/A
File opened for reading /proc/999/stat /tmp/linux_386.elf N/A
File opened for reading /proc/filesystems /usr/bin/systemctl N/A
File opened for reading /proc/1776/stat /tmp/linux_386.elf N/A
File opened for reading /proc/411/stat /tmp/linux_386.elf N/A
File opened for reading /proc/688/stat /tmp/linux_386.elf N/A
File opened for reading /proc/750/stat /tmp/linux_386.elf N/A

GoLang User-Agent

Description Indicator Process Target
HTTP User-Agent header Go-http-client/1.1 N/A N/A

Processes

/etc/32678

[/etc/32678]

/usr/bin/basename

[basename /usr/sbin/service]

/tmp/linux_386.elf

[/tmp/linux_386.elf ]

/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 daemon-reload]

/usr/local/bin/systemctl

[systemctl daemon-reload]

/usr/sbin/systemctl

[systemctl daemon-reload]

/usr/bin/systemctl

[systemctl daemon-reload]

/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 linux.service]

/usr/bin/systemctl

[systemctl start linux.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]

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 2.59.151.111:8080 tcp
US 2.59.151.111:808 2.59.151.111 tcp
N/A 10.127.0.1:22 tcp

Files

/etc/32678

MD5 768eaf287796da19e1cf5e0b2fb1b161
SHA1 6a1ce2ee5ccc86d1f33806feb14547b35290df2a
SHA256 1d22620dfb2a6715e5d745aed5cf841ede0e75e1747f12b9b925a2d346bc7ecb
SHA512 e6af30c9df4f7f47696069511e64ecbc8e841629d692ee4056503df3533fb7a7a74960698826260355e1dba7b6c562482a27a39bb51a4237473ce4b68472d620

/etc/init.d/linux_kill

MD5 3909975f7cc0d1121c1819b800069f31
SHA1 3e68de708c2e6c40fab6794afdee3104e5590189
SHA256 6876dac71f13a068afb863d257134275f2edba43b2acaf4924fabf97c079070b
SHA512 50600cceeb03b05f45ae61d890caee9f51ff390b6776930866e527e071d65d08241fc66673fd9b99d62fbc77d3c00fc3de4d7378cbc42f5daba5d83072b0906e

/boot/System.img.config

MD5 d21d21cb8de14e90f180b9c1f79276b3
SHA1 b83ccf62b44343b28181924e5047fb034421e124
SHA256 71ccac9d63fd1c2799963f5e5d87ee62f0c306741ae796dc4ea3777bdb0e8f09
SHA512 5ba5ea34dbe8d8bf62a64640e86c449aa07153c5c4aac88a01db879829feb28f312cb5ad2869d3a0e3679c8159ebddbe7c863b439e4593a13960a1dcfcc00b3c

/etc/profile.d/bash_config.sh

MD5 cfb4e51061485fe91169381fbdc1538e
SHA1 9a85b9b766a15b01737a41d680e4593b7a9bde87
SHA256 897f37267d0ceaa2fbdaa09847f5d08e6f8b01a0348a0d666264b0f10acd0c90
SHA512 fb154ec711d2090a7461da4db8ddad2b522649a27e74162ecb203f539b1729430288bc02d78d2071bde9c4bbc005693403a57612ef50277d52f816cb94524216

/.img

MD5 d73d3376908ea075a939e3871ad0fabe
SHA1 320ff65831247ba199515f1b94df26cc8a3e5f76
SHA256 edbdabe30d8236a2c0a4eb89dfd597552130e4c1a4e93f8fe1568920442ad73a
SHA512 57b83fef88620598beb5d65626bf757d0abef242d2d6a01796a61474dedc5095a4a9d0f292b6abb450cad3d4410ab8456253600f58ddb66cfe6d79e1c8415536