Malware Analysis Report

2025-05-05 22:14

Sample ID 250416-xex88sylt2
Target linux_mipsel.elf
SHA256 d3030e1575b48293f9364353127bd44892ec65120c11d1710eead510373aab55
Tags
kaiji 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

d3030e1575b48293f9364353127bd44892ec65120c11d1710eead510373aab55

Threat Level: Known bad

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

Malicious Activity Summary

kaiji discovery execution persistence privilege_escalation

Kaiji

Kaiji family

Executes dropped EXE

Creates/modifies Cron job

Changes its process name

Enumerates kernel/hardware configuration

Reads runtime system information

System Network Configuration Discovery

Command and Scripting Interpreter: Unix Shell

MITRE ATT&CK

Analysis: static1

Detonation Overview

Reported

2025-04-16 18:46

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 18:46

Reported

2025-04-16 18:49

Platform

debian9-mipsel-20250410-en

Max time kernel

149s

Max time network

150s

Command Line

[/tmp/linux_mipsel.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 /bin/sh N/A

Creates/modifies Cron job

execution persistence privilege_escalation
Description Indicator Process Target
File opened for modification /etc/crontab /bin/sh 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_mipsel.elf N/A

Command and Scripting Interpreter: Unix Shell

execution
Description Indicator Process Target
N/A N/A /bin/sh N/A
N/A N/A /bin/sh N/A

Enumerates kernel/hardware configuration

discovery
Description Indicator Process Target
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/kernel/mm/transparent_hugepage/hpage_pmd_size /tmp/linux_mipsel.elf N/A
File opened for reading /sys/kernel/mm/transparent_hugepage/hpage_pmd_size /tmp/linux_mipsel.elf N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A
File opened for reading /sys/fs/kdbus/0-system/bus /bin/systemctl N/A

Reads runtime system information

discovery
Description Indicator Process Target
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/sed N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/filesystems /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/cmdline /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/self/stat /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A
File opened for reading /proc/1/environ /bin/systemctl N/A

System Network Configuration Discovery

discovery
Description Indicator Process Target
N/A N/A /tmp/linux_mipsel.elf N/A
N/A N/A /tmp/linux_mipsel.elf N/A

Processes

/tmp/linux_mipsel.elf

[/tmp/linux_mipsel.elf]

/tmp/linux_mipsel.elf

[/tmp/linux_mipsel.elf ]

/bin/sh

[/bin/sh -c /etc/32676&]

/etc/32676

[/etc/32676]

/usr/sbin/service

[service crond start]

/usr/bin/basename

[basename /usr/sbin/service]

/bin/sleep

[sleep 60]

/usr/bin/basename

[basename /usr/sbin/service]

/bin/systemctl

[systemctl --quiet is-active multi-user.target]

/bin/systemctl

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

/bin/sed

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

/bin/systemctl

[systemctl -p Triggers show dbus.socket]

/bin/systemctl

[systemctl -p Triggers show ssh.socket]

/bin/systemctl

[systemctl -p Triggers show syslog.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-fsckd.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-initctl.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-journald-audit.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-journald-dev-log.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-journald.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-networkd.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-rfkill.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-udevd-control.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-udevd-kernel.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]

/sbin/systemctl

[systemctl start crond.service]

/bin/systemctl

[systemctl start crond.service]

/bin/sh

[/bin/sh -c echo "*/1 * * * * root /.mod " >> /etc/crontab]

/usr/bin/renice

[renice -20 717]

/bin/mount

[mount -o bind /tmp/ /proc/717]

/usr/sbin/service

[service cron start]

/usr/bin/basename

[basename /usr/sbin/service]

/usr/bin/basename

[basename /usr/sbin/service]

/bin/systemctl

[systemctl --quiet is-active multi-user.target]

/bin/systemctl

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

/bin/sed

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

/bin/systemctl

[systemctl -p Triggers show dbus.socket]

/bin/systemctl

[systemctl -p Triggers show ssh.socket]

/bin/systemctl

[systemctl -p Triggers show syslog.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-fsckd.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-initctl.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-journald-audit.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-journald-dev-log.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-journald.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-networkd.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-rfkill.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-udevd-control.socket]

/bin/systemctl

[systemctl -p Triggers show systemd-udevd-kernel.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]

/sbin/systemctl

[systemctl start cron.service]

/bin/systemctl

[systemctl start cron.service]

/bin/systemctl

[systemctl start crond.service]

/bin/sleep

[sleep 60]

/bin/sleep

[sleep 60]

Network

Country Destination Domain Proto
AU 1.1.1.1:53 www.google.com udp
AU 1.1.1.1:53 www.google.com udp
US 154.40.47.248:888 tcp

Files

/etc/.walk

MD5 9dda994087c2bc35d06b0eb91ae7aaf2
SHA1 ef819199d97a4c059d7554b5a4e9abd43a047236
SHA256 54dd5f1b76931783b563f469f8376e8089be1e75a3e067e7697528e01cd4ec44
SHA512 673051f1109c74e7c8982fbfe521ce12d676fba52f9cd6a3fd490056b1f978970b359061524ea13e32e9548f37afd54833fb3df53c372ea85be1161538184675

/etc/.walk

MD5 4fcae83c2720754f59d2a4f2af72735e
SHA1 a24d5cbb1d3b0e5c191ba64c61fad49c4baa5a7a
SHA256 5df5b1bb2147e17de64a4a96a10915458c2080c36d7dbe6a47d6857fb2a02220
SHA512 62c335b961167260e203fe13fe45598aebdf33b4e25b85927c5fec8d57b92ce5dc883524aa4ec58bde5e5168488a903b2118c062561a497932e93b9da253c402

/etc/opt.services.cfg

MD5 06a141032d508ea7639d82c044851727
SHA1 e49bf29f0c21f0e5a5d0ccee733ed1626df57d6b
SHA256 d3030e1575b48293f9364353127bd44892ec65120c11d1710eead510373aab55
SHA512 8173fc77c9ba84dc1a980c907dec6d2a37e20b3dec5438189fb1990e6c161de5a7ebc033091be2bcd7b80fb1bfe1478eb9f81f6811c9417fd95d3419c9cc2e05

/etc/32676

MD5 585f408444cbca746945f0cb63f2c3f0
SHA1 0e44bae17174f04514e770ca7fc4bec1007e39cd
SHA256 ebb961c647363dfa90f302de378e0e61807b9b792fc86616635a713cca8f4299
SHA512 022241dbafad55164701f67ef5b84154e3af97c5dfe77dee7bf8406f2befbd2962bbf4f243432b2f41d6c2376b87fcf551fd6945e03ddb02a5619c2f0f69c596

/.mod

MD5 f5a3713282e43c200f30342f5ff5e2ea
SHA1 2b2ce1a207e2b691a074c6f78f71c4785aae426a
SHA256 6ab64e727571458d4884fb2fe82c27c467db0699cb8f648b3f0217c35d2b7511
SHA512 5bcb8cd360409147a486755f90e0cdd97183af02ce8de5135b7c6a8a010deb9ef12dcd5ee9a2a8fd2e159347f68e72d6b7fd75e943b4fcd928d7a74b97476013

/usr/bin/include/find

MD5 bb4edcad76062a76284c69f5fe4e50ea
SHA1 86055be4ce94fa3cffa9924e7b511e95df636606
SHA256 b7e25e128c130473f33c5135c78f591f35d7c4a7c5e1246c12eaa298db453474
SHA512 254acc62d2f83f5a4686adcf3fe6ad4697f392c288c5baa323830bb6f2466c303fd7bc9f237e98b2ca76bc3abb6b4c264e042be8c4291ae5cc21b2189d996521

/etc/profile.d/gateway.sh

MD5 c8f763c31589dc4e50bf4b3ae51a3a18
SHA1 6b4b735a4bd385c07eeebc2ca13d9bd29a175a74
SHA256 9f8972f2b1980f7d2b4483ea08970e491880a9c6a301a5868ecefebd3e19af70
SHA512 3bc66301adbac289bb7a4e022bd472fbba14906566d088325139224e7bc62396cfe6490094bc23364399807d7113914d8892efcdfd8d1f005e096994848b080a