c1265ee4-aed4-4e65-ac54-c64deb5e3b28

fur.sys :inline

Description

SophosLabs has discovered that threat actors are using a new driver loader called BURNTCIGAR to install a malicious driver signed with Microsoft.

  • UUID: c1265ee4-aed4-4e65-ac54-c64deb5e3b28
  • Created: 2023-05-07
  • Author: Guus Verbeek
  • Acknowledgement: |

DownloadBlock

This download link contains the malicious driver!

Commands

sc.exe create fur.sys binPath=C:\windows\temp\fur.sys type=kernel && sc.exe start fur.sys
Use CasePrivilegesOperating System
Elevate privilegeskernelWindows 10

Detections

YARA 🏹

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Exact Match

with header and size limitation

Threat Hunting

without header and size limitation

Sigma 🛡️

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Names

detects loading using name only

Hashes

detects loading using hashes only

Sysmon 🔎

Expand

Block

on hashes

Alert

on hashes

Resources


  • https://www.mandiant.com/resources/blog/hunting-attestation-signed-malware, https://news.sophos.com/en-us/2022/12/13/signed-driver-malware-moves-up-the-software-trust-chain/

  • Known Vulnerable Samples

    PropertyValue
    Filename
    Creation Timestamp2022-09-14 22:24:03
    MD56a066d2be83cf83f343d0550b0b8f206
    SHA18e126f4f35e228fdd3aa78d533225db7122d8945
    SHA2560d10c4b2f56364b475b60bd2933273c8b1ed2176353e59e65f968c61e93b7d99
    Authentihash MD55c23bab622d6bbabd23d29b4adaa4ae0
    Authentihash SHA19fbb6f9a22d1c676ff1b97a33d4c5e94f18aca5f
    Authentihash SHA256aab97fb324c883f1de71112e1d9fb716cef40636e39a3b9f4a5b8678cf7bde3f
    RichPEHeaderHash MD5ffdf660eb1ebf020a1d0a55a90712dfb
    RichPEHeaderHash SHA13e905e3d061d0d59de61fcf39c994fcb0ec1bab3
    RichPEHeaderHash SHA2562b3f99a94b7a7132854be769e27b331419c53989ef42f686d6f5ba09ddefefd6

    Download

    Certificates

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    Certificate 3300000057ee4d659a923e7c10000000000057
    FieldValue
    ToBeSigned (TBS) MD5fdc11a5676aed4e9cc0c09eeb7450dfb
    ToBeSigned (TBS) SHA14902077d9a05d4231b791d3b05bafa4a79132f03
    ToBeSigned (TBS) SHA2565db56c23d83bf67c7152e28ad4a684a7372b4ae4f52afe7a81ce91eef94caec3
    SubjectC=US, ST=Washington, L=Redmond, O=Microsoft Corporation, CN=Microsoft Windows Hardware Compatibility Publisher
    ValidFrom2022-06-07 18:08:06
    ValidTo2023-06-01 18:08:06
    Signature0a835e40cdb627d4f0a0d3dbbf64a46a05c132d0b5df9d11cd9c195d7037737057d57a342732ae68d67de47f460e7211c7c40dc29b0a079caff871c4834a9a2fc85e759de9b78659ad6fd79b7320e538e9ba5d52227ad67cc00b0a770ef662af3d743a558643ad89cfb015591709a69b6271a9b65db71898e7cb9964c6376dc474898301a6133198b486b518fdd9d7b9723dcffc441e026833f7c72e27986026c97b9184a0048b10d1fe6847ae467f02173f7a69120be780e5b6b9e6399402cc58735a31b537cc33578fbea443135a4a612359150bcf9ab316f6a9248bc71ef3f3480b9b3fa2341692bc3a121d80214688f7bd87d5ec56dcbd0ea61abf2c7ed2b739a07590adb596d401735d955f5f94c591d69ab4363a42f9fca549d439495711ff7990448c03724792ed4acf31f2b35b136c1b2f37aa82b1aabf7daf059dcb2e976e95311ec6e9cc53876dd09632cf512d39c801849a7c1088a565691953e07c7ff17b22518e982dd2dcc0feda8c834ca1f5e247aef1c3af5f13cd4b8cc1b6c0179bc876db88d677047c34366533e349796dbdea86389ad640710b7742ae8cc4ec88f10fa80ede4b1c93f81b55480fc8228216d54813df0327e74b3db9f3512a40c0568e4215827f9b7a2613deea72a7ec4df2def05e5559015049fe83edc83300526045cb128119e131b7d3573b268e24b0a25b9ad59f6301c8fc8f409322
    SignatureAlgorithmOID1.2.840.113549.1.1.11
    IsCertificateAuthorityFalse
    SerialNumber3300000057ee4d659a923e7c10000000000057
    Version3
    Certificate 330000000d690d5d7893d076df00000000000d
    FieldValue
    ToBeSigned (TBS) MD583f69422963f11c3c340b81712eef319
    ToBeSigned (TBS) SHA10c5e5f24590b53bc291e28583acb78e5adc95601
    ToBeSigned (TBS) SHA256d8be9e4d9074088ef818bc6f6fb64955e90378b2754155126feebbbd969cf0ae
    SubjectC=US, ST=Washington, L=Redmond, O=Microsoft Corporation, CN=Microsoft Windows Third Party Component CA 2014
    ValidFrom2014-10-15 20:31:27
    ValidTo2029-10-15 20:41:27
    Signature96b5c33b31f27b6ba11f59dd742c3764b1bca093f9f33347e9f95df21d89f4579ee33f10a3595018053b142941b6a70e5b81a2ccbd8442c1c4bed184c2c4bd0c8c47bcbd8886fb5a0896ae2c2fdfbf9366a32b20ca848a6945273f732332936a23e9fffdd918edceffbd6b41738d579cf8b46d499805e6a335a9f07e6e86c06ba8086725afc0998cdba7064d4093188ba959e69914b912178144ac57c3ae8eae947bcb3b8edd7ab4715bba2bc3c7d085234b371277a54a2f7f1ab763b94459ed9230cce47c099212111f52f51e0291a4d7d7e58f8047ff189b7fd19c0671dcf376197790d52a0fbc6c12c4c50c2066f50e2f5093d8cafb7fe556ed09d8a753b1c72a6978dcf05fe74b20b6af63b5e1b15c804e9c7aa91d4df72846782106954d32dd6042e4b61ac4f24636de357302c1b5e55fb92b59457a9243d7c4e963dd368f76c728caa8441be8321a66cde5485c4a0a602b469206609698dcd933d721777f886dac4772daa2466eab64682bd24e98fb35cc7fec3f136d11e5db77edc1c37e1f6a4a14f8b4a721c671866770cdd819a35d1fa09b9a7cc55d4d728e74077fa74d00fcdd682412772a557527cda92c1d8e7c19ee692c9f7425338208db38cc7cc74f6c3a6bc237117872fe55596460333e2edfc42de72cd7fb0a82256fb8d70c84a5e1c4746e2a95329ea0fecdb4188fd33bad32b2b19ab86d0543fbff0d0f
    SignatureAlgorithmOID1.2.840.113549.1.1.11
    IsCertificateAuthorityTrue
    SerialNumber330000000d690d5d7893d076df00000000000d
    Version3

    Imports

    Expand
    • ntoskrnl.exe
    • FLTMGR.SYS
    • NETIO.SYS
    • WDFLDR.SYS
    • ntoskrnl.exe
    • HAL.dll

    Imported Functions

    Expand
    • ObQueryNameString
    • FltUnregisterFilter
    • WskRegister
    • WdfVersionBind
    • ExAllocatePool
    • NtQuerySystemInformation
    • ExFreePoolWithTag
    • IoAllocateMdl
    • MmProbeAndLockPages
    • MmMapLockedPagesSpecifyCache
    • MmUnlockPages
    • IoFreeMdl
    • KeQueryActiveProcessors
    • KeSetSystemAffinityThread
    • KeRevertToUserAffinityThread
    • DbgPrint
    • KeQueryPerformanceCounter

    Exported Functions

    Expand

    Sections

    Expand
    • .text
    • .rdata
    • .data
    • .pdata
    • PAGE
    • INIT
    • .73h0
    • .73h1
    • .73h2
    • .reloc

    Signature

    Expand
    {
      "Certificates": [
        {
          "IsCertificateAuthority": false,
          "SerialNumber": "3300000057ee4d659a923e7c10000000000057",
          "Signature": "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",
          "SignatureAlgorithmOID": "1.2.840.113549.1.1.11",
          "Subject": "C=US, ST=Washington, L=Redmond, O=Microsoft Corporation, CN=Microsoft Windows Hardware Compatibility Publisher",
          "TBS": {
            "MD5": "fdc11a5676aed4e9cc0c09eeb7450dfb",
            "SHA1": "4902077d9a05d4231b791d3b05bafa4a79132f03",
            "SHA256": "5db56c23d83bf67c7152e28ad4a684a7372b4ae4f52afe7a81ce91eef94caec3",
            "SHA384": "c952d7f0e0ea5216ce4400601fb7c0829f0f3fcd6eb2b5b9112fbe45d133e00c4abd660f8e1794f7ac4ef95123e2c0ab"
          },
          "ValidFrom": "2022-06-07 18:08:06",
          "ValidTo": "2023-06-01 18:08:06",
          "Version": 3
        },
        {
          "IsCertificateAuthority": true,
          "SerialNumber": "330000000d690d5d7893d076df00000000000d",
          "Signature": "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",
          "SignatureAlgorithmOID": "1.2.840.113549.1.1.11",
          "Subject": "C=US, ST=Washington, L=Redmond, O=Microsoft Corporation, CN=Microsoft Windows Third Party Component CA 2014",
          "TBS": {
            "MD5": "83f69422963f11c3c340b81712eef319",
            "SHA1": "0c5e5f24590b53bc291e28583acb78e5adc95601",
            "SHA256": "d8be9e4d9074088ef818bc6f6fb64955e90378b2754155126feebbbd969cf0ae",
            "SHA384": "260ad59ba706420f68ba212931153bd89f760c464b21be55fba9d014fff322407859d4ebfb78ea9a3330f60dc9821a63"
          },
          "ValidFrom": "2014-10-15 20:31:27",
          "ValidTo": "2029-10-15 20:41:27",
          "Version": 3
        }
      ],
      "CertificatesInfo": "",
      "Signer": [
        {
          "Issuer": "C=US, ST=Washington, L=Redmond, O=Microsoft Corporation, CN=Microsoft Windows Third Party Component CA 2014",
          "SerialNumber": "3300000057ee4d659a923e7c10000000000057",
          "Version": 1
        }
      ],
      "SignerInfo": ""
    }
    

    source

    last_updated: 2024-09-26