Malware Analysis Report

2024-08-06 16:16

Sample ID 240701-3apdeszcqr
Target koala.exe
SHA256 f4967fd913dc43ba20eeda786ce3da4119df5d86b4536c3b68f44c2ed09e42bf
Tags
chaos persistence ransomware
score
10/10

Table of Contents

Analysis Overview

MITRE ATT&CK Matrix

Analysis: static1

Detonation Overview

Signatures

Analysis: behavioral1

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis: behavioral2

Detonation Overview

Command Line

Signatures

Processes

Network

Files

Analysis Overview

score
10/10

SHA256

f4967fd913dc43ba20eeda786ce3da4119df5d86b4536c3b68f44c2ed09e42bf

Threat Level: Known bad

The file koala.exe was found to be: Known bad.

Malicious Activity Summary

chaos persistence ransomware

Chaos family

Chaos

Chaos Ransomware

Renames multiple (62) files with added filename extension

Drops startup file

Checks computer location settings

Executes dropped EXE

Adds Run key to start application

Drops desktop.ini file(s)

Unsigned PE

Enumerates physical storage devices

Suspicious behavior: EnumeratesProcesses

Suspicious use of AdjustPrivilegeToken

Modifies registry class

Suspicious use of FindShellTrayWindow

Opens file in notepad (likely ransom note)

Suspicious behavior: AddClipboardFormatListener

Suspicious use of WriteProcessMemory

MITRE ATT&CK Matrix V13

Initial Access
TA0001
Execution
TA0002
Persistence
TA0003
Boot or Logon Autostart Execution
T1547
Registry Run Keys / Startup Folder
T1547.001
Privilege Escalation
TA0004
Boot or Logon Autostart Execution
T1547
Registry Run Keys / Startup Folder
T1547.001
Defense Evasion
TA0005
Modify Registry
T1112
Credential Access
TA0006
Discovery
TA0007
System Information Discovery
T1082
Query Registry
T1012
Lateral Movement
TA0008
Collection
TA0009
Exfiltration
TA0010
Command and Control
TA0011
Impact
TA0040
Resource Development
TA0042
Reconnaissance
TA0043

Analysis: static1

Detonation Overview

Reported

2024-07-01 23:18

Signatures

Chaos Ransomware

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

Chaos family

chaos

Unsigned PE

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

Analysis: behavioral1

Detonation Overview

Submitted

2024-07-01 23:18

Reported

2024-07-01 23:22

Platform

win7-20240221-en

Max time kernel

118s

Max time network

119s

Command Line

"C:\Users\Admin\AppData\Local\Temp\koala.exe"

Signatures

Chaos

ransomware chaos

Chaos Ransomware

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

Drops startup file

Description Indicator Process Target
File created C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\svchost.url C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Executes dropped EXE

Description Indicator Process Target
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Adds Run key to start application

persistence
Description Indicator Process Target
Set value (str) \REGISTRY\USER\S-1-5-21-2297530677-1229052932-2803917579-1000\Software\Microsoft\Windows\CurrentVersion\Run\Microsoft Store = "C:\\Users\\Admin\\AppData\\Roaming\\svchost.exe" C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Drops desktop.ini file(s)

Description Indicator Process Target
File created C:\Users\Admin\Saved Games\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Searches\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Music\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created F:\$RECYCLE.BIN\S-1-5-21-2297530677-1229052932-2803917579-1000\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Contacts\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Pictures\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Videos\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Favorites\Links\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Favorites\Links for United States\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Desktop\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Links\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Documents\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Downloads\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Favorites\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Enumerates physical storage devices

Opens file in notepad (likely ransom note)

ransomware
Description Indicator Process Target
N/A N/A C:\Windows\system32\NOTEPAD.EXE N/A

Suspicious behavior: AddClipboardFormatListener

Description Indicator Process Target
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Suspicious behavior: EnumeratesProcesses

Description Indicator Process Target
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Suspicious use of AdjustPrivilegeToken

Description Indicator Process Target
Token: SeDebugPrivilege N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
Token: SeDebugPrivilege N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Suspicious use of FindShellTrayWindow

Description Indicator Process Target
N/A N/A C:\Windows\system32\NOTEPAD.EXE N/A

Suspicious use of WriteProcessMemory

Description Indicator Process Target
PID 2992 wrote to memory of 3040 N/A C:\Users\Admin\AppData\Local\Temp\koala.exe C:\Users\Admin\AppData\Roaming\svchost.exe
PID 2992 wrote to memory of 3040 N/A C:\Users\Admin\AppData\Local\Temp\koala.exe C:\Users\Admin\AppData\Roaming\svchost.exe
PID 2992 wrote to memory of 3040 N/A C:\Users\Admin\AppData\Local\Temp\koala.exe C:\Users\Admin\AppData\Roaming\svchost.exe
PID 3040 wrote to memory of 1464 N/A C:\Users\Admin\AppData\Roaming\svchost.exe C:\Windows\system32\NOTEPAD.EXE
PID 3040 wrote to memory of 1464 N/A C:\Users\Admin\AppData\Roaming\svchost.exe C:\Windows\system32\NOTEPAD.EXE
PID 3040 wrote to memory of 1464 N/A C:\Users\Admin\AppData\Roaming\svchost.exe C:\Windows\system32\NOTEPAD.EXE

Processes

C:\Users\Admin\AppData\Local\Temp\koala.exe

"C:\Users\Admin\AppData\Local\Temp\koala.exe"

C:\Users\Admin\AppData\Roaming\svchost.exe

"C:\Users\Admin\AppData\Roaming\svchost.exe"

C:\Windows\system32\NOTEPAD.EXE

"C:\Windows\system32\NOTEPAD.EXE" C:\Users\Admin\AppData\Roaming\read_it.txt

Network

N/A

Files

memory/2992-0-0x000007FEF5DD3000-0x000007FEF5DD4000-memory.dmp

memory/2992-1-0x0000000000960000-0x000000000096A000-memory.dmp

C:\Users\Admin\AppData\Roaming\svchost.exe

MD5 607bf2b302c3941815dc159e356f06fd
SHA1 3d86bfc813a47dbede8f9420de418b2143e791e4
SHA256 f4967fd913dc43ba20eeda786ce3da4119df5d86b4536c3b68f44c2ed09e42bf
SHA512 1317171b290e0e0fc667d9b4210a34744e0b21416c56a7e56bc747851c6f1db375eb014b752ef304cd6527c5b288e49840ccf663b4a6e607afd1717653b095ea

memory/3040-7-0x0000000000C10000-0x0000000000C1A000-memory.dmp

memory/3040-8-0x000007FEF5DD0000-0x000007FEF67BC000-memory.dmp

C:\Users\Admin\Downloads\read_it.txt

MD5 adc425a1c306a33d9d727120895abf29
SHA1 0613ad669cae1af9b90cb463d19eee9d7757c4e3
SHA256 5162a83bf8f5d56067cb93d6e35eed14bf10703e485a261cd7cca400ca88d31a
SHA512 ec2630f84c648a8bed9c69c928fbca2e187292e0e25a7507ada3e1f36a2403d7243c7b166b8a2f7b19ba877835a8a762c54d63940a03dce0597a1c159890be55

memory/3040-119-0x000007FEF5DD0000-0x000007FEF67BC000-memory.dmp

memory/3040-121-0x000007FEF5DD0000-0x000007FEF67BC000-memory.dmp

memory/3040-122-0x000007FEF5DD0000-0x000007FEF67BC000-memory.dmp

Analysis: behavioral2

Detonation Overview

Submitted

2024-07-01 23:18

Reported

2024-07-01 23:22

Platform

win10v2004-20240508-en

Max time kernel

93s

Max time network

96s

Command Line

"C:\Users\Admin\AppData\Local\Temp\koala.exe"

Signatures

Chaos

ransomware chaos

Chaos Ransomware

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

Renames multiple (62) files with added filename extension

ransomware

Checks computer location settings

Description Indicator Process Target
Key value queried \REGISTRY\USER\S-1-5-21-2804150937-2146708401-419095071-1000\Control Panel\International\Geo\Nation C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
Key value queried \REGISTRY\USER\S-1-5-21-2804150937-2146708401-419095071-1000\Control Panel\International\Geo\Nation C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Drops startup file

Description Indicator Process Target
File created C:\Users\Admin\AppData\Roaming\Microsoft\Windows\Start Menu\Programs\Startup\svchost.url C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Executes dropped EXE

Description Indicator Process Target
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Adds Run key to start application

persistence
Description Indicator Process Target
Set value (str) \REGISTRY\USER\S-1-5-21-2804150937-2146708401-419095071-1000\SOFTWARE\Microsoft\Windows\CurrentVersion\Run\Microsoft Store = "C:\\Users\\Admin\\AppData\\Roaming\\svchost.exe" C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Drops desktop.ini file(s)

Description Indicator Process Target
File created C:\Users\Admin\Contacts\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Music\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Favorites\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Videos\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Desktop\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Pictures\Camera Roll\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Pictures\Saved Pictures\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\OneDrive\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Favorites\Links\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Downloads\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Pictures\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Saved Games\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Searches\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Documents\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created C:\Users\Admin\Links\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A
File created F:\$RECYCLE.BIN\S-1-5-21-2804150937-2146708401-419095071-1000\desktop.ini C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Enumerates physical storage devices

Modifies registry class

Description Indicator Process Target
Key created \REGISTRY\USER\S-1-5-21-2804150937-2146708401-419095071-1000_Classes\Local Settings C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Opens file in notepad (likely ransom note)

ransomware
Description Indicator Process Target
N/A N/A C:\Windows\system32\NOTEPAD.EXE N/A

Suspicious behavior: AddClipboardFormatListener

Description Indicator Process Target
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Suspicious behavior: EnumeratesProcesses

Description Indicator Process Target
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A
N/A N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Suspicious use of AdjustPrivilegeToken

Description Indicator Process Target
Token: SeDebugPrivilege N/A C:\Users\Admin\AppData\Local\Temp\koala.exe N/A
Token: SeDebugPrivilege N/A C:\Users\Admin\AppData\Roaming\svchost.exe N/A

Suspicious use of WriteProcessMemory

Description Indicator Process Target
PID 4428 wrote to memory of 2716 N/A C:\Users\Admin\AppData\Local\Temp\koala.exe C:\Users\Admin\AppData\Roaming\svchost.exe
PID 4428 wrote to memory of 2716 N/A C:\Users\Admin\AppData\Local\Temp\koala.exe C:\Users\Admin\AppData\Roaming\svchost.exe
PID 2716 wrote to memory of 3108 N/A C:\Users\Admin\AppData\Roaming\svchost.exe C:\Windows\system32\NOTEPAD.EXE
PID 2716 wrote to memory of 3108 N/A C:\Users\Admin\AppData\Roaming\svchost.exe C:\Windows\system32\NOTEPAD.EXE

Processes

C:\Users\Admin\AppData\Local\Temp\koala.exe

"C:\Users\Admin\AppData\Local\Temp\koala.exe"

C:\Users\Admin\AppData\Roaming\svchost.exe

"C:\Users\Admin\AppData\Roaming\svchost.exe"

C:\Windows\system32\NOTEPAD.EXE

"C:\Windows\system32\NOTEPAD.EXE" C:\Users\Admin\AppData\Roaming\read_it.txt

Network

Country Destination Domain Proto
US 8.8.8.8:53 8.8.8.8.in-addr.arpa udp
US 8.8.8.8:53 58.55.71.13.in-addr.arpa udp
US 8.8.8.8:53 2.159.190.20.in-addr.arpa udp
US 8.8.8.8:53 240.197.17.2.in-addr.arpa udp
US 8.8.8.8:53 228.249.119.40.in-addr.arpa udp
US 8.8.8.8:53 103.169.127.40.in-addr.arpa udp
US 8.8.8.8:53 198.187.3.20.in-addr.arpa udp
US 8.8.8.8:53 172.210.232.199.in-addr.arpa udp
US 8.8.8.8:53 249.197.17.2.in-addr.arpa udp
US 8.8.8.8:53 13.227.111.52.in-addr.arpa udp

Files

memory/4428-0-0x00000000005F0000-0x00000000005FA000-memory.dmp

memory/4428-1-0x00007FFF4ABA3000-0x00007FFF4ABA5000-memory.dmp

C:\Users\Admin\AppData\Roaming\svchost.exe

MD5 607bf2b302c3941815dc159e356f06fd
SHA1 3d86bfc813a47dbede8f9420de418b2143e791e4
SHA256 f4967fd913dc43ba20eeda786ce3da4119df5d86b4536c3b68f44c2ed09e42bf
SHA512 1317171b290e0e0fc667d9b4210a34744e0b21416c56a7e56bc747851c6f1db375eb014b752ef304cd6527c5b288e49840ccf663b4a6e607afd1717653b095ea

memory/2716-14-0x00007FFF4ABA0000-0x00007FFF4B661000-memory.dmp

C:\Users\Admin\Pictures\read_it.txt

MD5 adc425a1c306a33d9d727120895abf29
SHA1 0613ad669cae1af9b90cb463d19eee9d7757c4e3
SHA256 5162a83bf8f5d56067cb93d6e35eed14bf10703e485a261cd7cca400ca88d31a
SHA512 ec2630f84c648a8bed9c69c928fbca2e187292e0e25a7507ada3e1f36a2403d7243c7b166b8a2f7b19ba877835a8a762c54d63940a03dce0597a1c159890be55

memory/2716-150-0x00007FFF4ABA0000-0x00007FFF4B661000-memory.dmp