Analysis

  • max time kernel
    160s
  • max time network
    172s
  • platform
    windows10-2004_x64
  • resource
    win10v2004-20240226-en
  • resource tags

    arch:x64arch:x86image:win10v2004-20240226-enlocale:en-usos:windows10-2004-x64system
  • submitted
    17-04-2024 14:55

General

  • Target

    bc822ed934731c6843e138a7b5a0f643b6852ee233b0fb861040bd95111d09f5.exe

  • Size

    239KB

  • MD5

    a520a1746783fd618b1f805ce48b313f

  • SHA1

    d66c729c5d5b49c0e02f8f692425a6d4743f58cf

  • SHA256

    bc822ed934731c6843e138a7b5a0f643b6852ee233b0fb861040bd95111d09f5

  • SHA512

    04e948f7e1df4856d65e30abfcca3a9ff7417f3e572df32b98d268bd982f87d97fc0a4a955ebe6e75de13d1d0e22132269e4c74124927385010feb00bd34066e

  • SSDEEP

    6144:IfULzEiwjQjbSnDuWi+Ygh5pUTQYJkge:hXEiwjhn4gh5Wtkv

Malware Config

Extracted

Family

tofsee

C2

vanaheim.cn

jotunheim.name

Signatures

  • Tofsee

    Backdoor/botnet which carries out malicious activities based on commands from a C2 server.

  • Creates new service(s) 1 TTPs
  • Modifies Windows Firewall 2 TTPs 1 IoCs
  • Sets service image path in registry 2 TTPs 1 IoCs
  • Checks computer location settings 2 TTPs 1 IoCs

    Looks up country code configured in the registry, likely geofence.

  • Deletes itself 1 IoCs
  • Executes dropped EXE 1 IoCs
  • Drops file in System32 directory 1 IoCs
  • Suspicious use of SetThreadContext 1 IoCs
  • Launches sc.exe 3 IoCs

    Sc.exe is a Windows utlilty to control services on the system.

  • Enumerates physical storage devices 1 TTPs

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

  • Program crash 2 IoCs
  • Modifies data under HKEY_USERS 3 IoCs
  • Suspicious use of WriteProcessMemory 23 IoCs

Processes

  • C:\Users\Admin\AppData\Local\Temp\bc822ed934731c6843e138a7b5a0f643b6852ee233b0fb861040bd95111d09f5.exe
    "C:\Users\Admin\AppData\Local\Temp\bc822ed934731c6843e138a7b5a0f643b6852ee233b0fb861040bd95111d09f5.exe"
    1⤵
    • Checks computer location settings
    • Suspicious use of WriteProcessMemory
    PID:5104
    • C:\Windows\SysWOW64\cmd.exe
      "C:\Windows\System32\cmd.exe" /C mkdir C:\Windows\SysWOW64\yuxzcliu\
      2⤵
        PID:4384
      • C:\Windows\SysWOW64\cmd.exe
        "C:\Windows\System32\cmd.exe" /C move /Y "C:\Users\Admin\AppData\Local\Temp\vhpmsflj.exe" C:\Windows\SysWOW64\yuxzcliu\
        2⤵
          PID:4316
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" create yuxzcliu binPath= "C:\Windows\SysWOW64\yuxzcliu\vhpmsflj.exe /d\"C:\Users\Admin\AppData\Local\Temp\bc822ed934731c6843e138a7b5a0f643b6852ee233b0fb861040bd95111d09f5.exe\"" type= own start= auto DisplayName= "wifi support"
          2⤵
          • Launches sc.exe
          PID:4344
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" description yuxzcliu "wifi internet conection"
          2⤵
          • Launches sc.exe
          PID:3492
        • C:\Windows\SysWOW64\sc.exe
          "C:\Windows\System32\sc.exe" start yuxzcliu
          2⤵
          • Launches sc.exe
          PID:4840
        • C:\Windows\SysWOW64\netsh.exe
          "C:\Windows\System32\netsh.exe" advfirewall firewall add rule name="Host-process for services of Windows" dir=in action=allow program="C:\Windows\SysWOW64\svchost.exe" enable=yes>nul
          2⤵
          • Modifies Windows Firewall
          PID:4220
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -u -p 5104 -s 640
          2⤵
          • Program crash
          PID:2892
      • C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe
        "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe" --type=utility --utility-sub-type=asset_store.mojom.AssetStoreService --lang=en-US --service-sandbox-type=asset_store_service --no-appcompat-clear --mojo-platform-channel-handle=4048 --field-trial-handle=3060,i,1774866140584649235,8085848018931772189,262144 --variations-seed-version /prefetch:8
        1⤵
          PID:1984
        • C:\Windows\SysWOW64\WerFault.exe
          C:\Windows\SysWOW64\WerFault.exe -pss -s 452 -p 5104 -ip 5104
          1⤵
            PID:3896
          • C:\Windows\SysWOW64\yuxzcliu\vhpmsflj.exe
            C:\Windows\SysWOW64\yuxzcliu\vhpmsflj.exe /d"C:\Users\Admin\AppData\Local\Temp\bc822ed934731c6843e138a7b5a0f643b6852ee233b0fb861040bd95111d09f5.exe"
            1⤵
            • Executes dropped EXE
            • Suspicious use of SetThreadContext
            • Suspicious use of WriteProcessMemory
            PID:3668
            • C:\Windows\SysWOW64\svchost.exe
              svchost.exe
              2⤵
              • Sets service image path in registry
              • Deletes itself
              • Drops file in System32 directory
              • Modifies data under HKEY_USERS
              PID:1976
            • C:\Windows\SysWOW64\WerFault.exe
              C:\Windows\SysWOW64\WerFault.exe -u -p 3668 -s 532
              2⤵
              • Program crash
              PID:780
          • C:\Windows\SysWOW64\WerFault.exe
            C:\Windows\SysWOW64\WerFault.exe -pss -s 480 -p 3668 -ip 3668
            1⤵
              PID:3440

            Network

            MITRE ATT&CK Matrix ATT&CK v13

            Persistence

            Create or Modify System Process

            2
            T1543

            Windows Service

            2
            T1543.003

            Boot or Logon Autostart Execution

            1
            T1547

            Registry Run Keys / Startup Folder

            1
            T1547.001

            Privilege Escalation

            Create or Modify System Process

            2
            T1543

            Windows Service

            2
            T1543.003

            Boot or Logon Autostart Execution

            1
            T1547

            Registry Run Keys / Startup Folder

            1
            T1547.001

            Defense Evasion

            Impair Defenses

            1
            T1562

            Disable or Modify System Firewall

            1
            T1562.004

            Modify Registry

            1
            T1112

            Discovery

            Query Registry

            1
            T1012

            System Information Discovery

            2
            T1082

            Replay Monitor

            Loading Replay Monitor...

            Downloads

            • C:\Users\Admin\AppData\Local\Temp\vhpmsflj.exe
              Filesize

              13.9MB

              MD5

              1269d2e36dff38e65ad46151622dc8a4

              SHA1

              29d66279ce0964fef9805132f218bd8c7ddf4ae9

              SHA256

              18ae6305509b9ca1ada1ae0c4bbd1f5dbe0643191895d799b077b550064030fd

              SHA512

              b41647742bbe88af785d73720fcd9d4575a95715e690dab516bbb00e10ad6be9dcbc42dd82ab8f979bf810eb59efaf408c42d95c1de65321a11ab93b7061e430

            • memory/1976-56-0x00000000027E0000-0x00000000027E5000-memory.dmp
              Filesize

              20KB

            • memory/1976-54-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-42-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-64-0x00000000027F0000-0x00000000027F7000-memory.dmp
              Filesize

              28KB

            • memory/1976-63-0x0000000007240000-0x000000000764B000-memory.dmp
              Filesize

              4.0MB

            • memory/1976-39-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-43-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-41-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-44-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-45-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-47-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-20-0x0000000000680000-0x0000000000695000-memory.dmp
              Filesize

              84KB

            • memory/1976-40-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-48-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-26-0x0000000000680000-0x0000000000695000-memory.dmp
              Filesize

              84KB

            • memory/1976-28-0x0000000000680000-0x0000000000695000-memory.dmp
              Filesize

              84KB

            • memory/1976-29-0x0000000002200000-0x000000000240F000-memory.dmp
              Filesize

              2.1MB

            • memory/1976-32-0x0000000002200000-0x000000000240F000-memory.dmp
              Filesize

              2.1MB

            • memory/1976-33-0x00000000019F0000-0x00000000019F6000-memory.dmp
              Filesize

              24KB

            • memory/1976-36-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-25-0x0000000000680000-0x0000000000695000-memory.dmp
              Filesize

              84KB

            • memory/1976-51-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-53-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-46-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-49-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-50-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-52-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/1976-59-0x00000000027E0000-0x00000000027E5000-memory.dmp
              Filesize

              20KB

            • memory/1976-60-0x0000000007240000-0x000000000764B000-memory.dmp
              Filesize

              4.0MB

            • memory/1976-55-0x0000000002550000-0x0000000002560000-memory.dmp
              Filesize

              64KB

            • memory/3668-23-0x0000000000400000-0x000000000085D000-memory.dmp
              Filesize

              4.4MB

            • memory/3668-19-0x0000000000400000-0x000000000085D000-memory.dmp
              Filesize

              4.4MB

            • memory/3668-18-0x0000000000A20000-0x0000000000B20000-memory.dmp
              Filesize

              1024KB

            • memory/5104-1-0x0000000000AF0000-0x0000000000BF0000-memory.dmp
              Filesize

              1024KB

            • memory/5104-3-0x0000000000400000-0x000000000085D000-memory.dmp
              Filesize

              4.4MB

            • memory/5104-4-0x0000000000400000-0x000000000085D000-memory.dmp
              Filesize

              4.4MB

            • memory/5104-2-0x00000000025B0000-0x00000000025C3000-memory.dmp
              Filesize

              76KB

            • memory/5104-17-0x0000000000400000-0x000000000085D000-memory.dmp
              Filesize

              4.4MB

            • memory/5104-9-0x00000000025B0000-0x00000000025C3000-memory.dmp
              Filesize

              76KB

            • memory/5104-8-0x0000000000400000-0x000000000085D000-memory.dmp
              Filesize

              4.4MB

            • memory/5104-7-0x0000000000AF0000-0x0000000000BF0000-memory.dmp
              Filesize

              1024KB

            • memory/5104-5-0x0000000000400000-0x000000000085D000-memory.dmp
              Filesize

              4.4MB