Resubmissions

04-10-2021 11:00

211004-m37gpsgccl 10

20-09-2021 11:57

210920-n4q2sagfap 10

Analysis

  • max time kernel
    77s
  • max time network
    32s
  • platform
    windows7_x64
  • resource
    win7-en-20210916
  • submitted
    20-09-2021 11:57

General

  • Target

    B06.exe

  • Size

    4.5MB

  • MD5

    49fb0e5a3415155c24d6839250cd7fed

  • SHA1

    69fa4c797df21b98740368c268cfd1919bf4a6e0

  • SHA256

    f2a155473c06ecad973676f1e2a8d228ab4a8adf32a87477c716f31fddf6cbaf

  • SHA512

    4bcf713b36e0c0bd1e12018cc835a988dbbb2d54556531ebddf97435fd430dab0393fe55e16de5b0c894a49fbea7829f2e6cba5214230f4ee70978a6a87ce397

Malware Config

Signatures

  • MedusaLocker

    Ransomware with several variants first seen in September 2019.

  • MedusaLocker Payload 1 IoCs
  • Deletes shadow copies 2 TTPs

    Ransomware often targets backup files to inhibit system recovery.

  • Modifies boot configuration data using bcdedit 1 TTPs 2 IoCs
  • Deletes System State backups 3 TTPs 2 IoCs

    Uses wbadmin.exe to inhibit system recovery.

  • Drops file in Drivers directory 12 IoCs
  • Modifies extensions of user files 29 IoCs

    Ransomware generally changes the extension on encrypted files.

  • Deletes itself 1 IoCs
  • Reads user/profile data of web browsers 2 TTPs

    Infostealers often target stored browser data, which can include saved credentials etc.

  • Adds Run key to start application 2 TTPs 2 IoCs
  • Drops desktop.ini file(s) 1 IoCs
  • Enumerates connected drives 3 TTPs 41 IoCs

    Attempts to read the root path of hard drives other than the default C: drive.

  • Drops file in System32 directory 64 IoCs
  • Drops file in Program Files directory 64 IoCs
  • Drops file in Windows directory 42 IoCs
  • Enumerates physical storage devices 1 TTPs

    Attempts to interact with connected storage/optical drive(s). Likely ransomware behaviour.

  • Interacts with shadow copies 2 TTPs 13 IoCs

    Shadow copies are often targeted by ransomware to inhibit system recovery.

  • Suspicious behavior: EnumeratesProcesses 64 IoCs
  • Suspicious use of AdjustPrivilegeToken 23 IoCs
  • Suspicious use of WriteProcessMemory 57 IoCs
  • System policy modification 1 TTPs 1 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\B06.exe
    "C:\Users\Admin\AppData\Local\Temp\B06.exe"
    1⤵
    • Drops file in Drivers directory
    • Modifies extensions of user files
    • Adds Run key to start application
    • Drops desktop.ini file(s)
    • Enumerates connected drives
    • Drops file in System32 directory
    • Drops file in Program Files directory
    • Drops file in Windows directory
    • Suspicious behavior: EnumeratesProcesses
    • Suspicious use of WriteProcessMemory
    • System policy modification
    PID:2032
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=c: /on=c: /maxsize=401MB
      2⤵
      • Interacts with shadow copies
      PID:616
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=c: /on=c: /maxsize=unbounded
      2⤵
      • Interacts with shadow copies
      PID:796
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=d: /on=d: /maxsize=401MB
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:1968
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=d: /on=d: /maxsize=unbounded
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:1064
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=e: /on=e: /maxsize=401MB
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:1188
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=e: /on=e: /maxsize=unbounded
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:1992
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=f: /on=f: /maxsize=401MB
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:608
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=f: /on=f: /maxsize=unbounded
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:456
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=g: /on=g: /maxsize=401MB
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:1936
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=g: /on=g: /maxsize=unbounded
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:216
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=h: /on=h: /maxsize=401MB
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:1756
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Resize ShadowStorage /for=h: /on=h: /maxsize=unbounded
      2⤵
      • Enumerates connected drives
      • Interacts with shadow copies
      PID:652
    • C:\Windows\system32\vssadmin.exe
      vssadmin.exe Delete Shadows /All /Quiet
      2⤵
      • Interacts with shadow copies
      PID:2040
    • C:\Windows\system32\bcdedit.exe
      bcdedit.exe /set {default} recoveryenabled No
      2⤵
      • Modifies boot configuration data using bcdedit
      PID:1028
    • C:\Windows\system32\bcdedit.exe
      bcdedit.exe /set {default} bootstatuspolicy ignoreallfailures
      2⤵
      • Modifies boot configuration data using bcdedit
      PID:1360
    • C:\Windows\system32\wbadmin.exe
      wbadmin DELETE SYSTEMSTATEBACKUP
      2⤵
      • Deletes System State backups
      • Drops file in Windows directory
      PID:1316
    • C:\Windows\system32\wbadmin.exe
      wbadmin DELETE SYSTEMSTATEBACKUP -deleteOldest
      2⤵
      • Deletes System State backups
      • Drops file in Windows directory
      PID:1396
    • C:\Windows\System32\Wbem\wmic.exe
      wmic.exe SHADOWCOPY /nointeractive
      2⤵
      • Suspicious use of AdjustPrivilegeToken
      PID:456
    • C:\Windows\system32\cmd.exe
      "C:\Windows\system32\cmd.exe" /c del C:\Users\Admin\AppData\Local\Temp\B06.exe >> NUL
      2⤵
      • Deletes itself
      PID:1032
  • C:\Windows\system32\vssvc.exe
    C:\Windows\system32\vssvc.exe
    1⤵
    • Suspicious use of AdjustPrivilegeToken
    PID:1816

Network

MITRE ATT&CK Matrix ATT&CK v6

Execution

Command-Line Interface

1
T1059

Persistence

Registry Run Keys / Startup Folder

1
T1060

Defense Evasion

File Deletion

3
T1107

Modify Registry

2
T1112

Credential Access

Credentials in Files

1
T1081

Discovery

Query Registry

1
T1012

Peripheral Device Discovery

1
T1120

System Information Discovery

2
T1082

Collection

Data from Local System

1
T1005

Impact

Inhibit System Recovery

4
T1490

Replay Monitor

Loading Replay Monitor...

Downloads

  • memory/216-63-0x0000000000000000-mapping.dmp
  • memory/456-73-0x0000000000000000-mapping.dmp
  • memory/456-61-0x0000000000000000-mapping.dmp
  • memory/608-60-0x0000000000000000-mapping.dmp
  • memory/616-54-0x0000000000000000-mapping.dmp
  • memory/652-65-0x0000000000000000-mapping.dmp
  • memory/796-55-0x0000000000000000-mapping.dmp
  • memory/1028-67-0x0000000000000000-mapping.dmp
  • memory/1032-74-0x0000000000000000-mapping.dmp
  • memory/1064-57-0x0000000000000000-mapping.dmp
  • memory/1188-58-0x0000000000000000-mapping.dmp
  • memory/1316-69-0x0000000000000000-mapping.dmp
  • memory/1316-70-0x000007FEFB9F1000-0x000007FEFB9F3000-memory.dmp
    Filesize

    8KB

  • memory/1360-68-0x0000000000000000-mapping.dmp
  • memory/1396-71-0x0000000000000000-mapping.dmp
  • memory/1756-64-0x0000000000000000-mapping.dmp
  • memory/1936-62-0x0000000000000000-mapping.dmp
  • memory/1968-56-0x0000000000000000-mapping.dmp
  • memory/1992-59-0x0000000000000000-mapping.dmp
  • memory/2032-53-0x000000013FBC0000-0x0000000140438000-memory.dmp
    Filesize

    8.5MB

  • memory/2040-66-0x0000000000000000-mapping.dmp