title: Malicious Base64 Encoded PowerShell Keywords in Command Lines
author: John Lambert (rule)
date: 2019/01/16
description: Detects base64 encoded strings used in hidden malicious PowerShell command
    lines
detection:
    SELECTION_1:
        EventID: 1
    SELECTION_10:
        CommandLine: '*AGMAaAB1AG4AawBfAHMAaQB6AGUA*'
    SELECTION_11:
        CommandLine: '*JABjAGgAdQBuAGsAXwBzAGkAegBlA*'
    SELECTION_12:
        CommandLine: '*JGNodW5rX3Npem*'
    SELECTION_13:
        CommandLine: '*QAYwBoAHUAbgBrAF8AcwBpAHoAZQ*'
    SELECTION_14:
        CommandLine: '*RjaHVua19zaXpl*'
    SELECTION_15:
        CommandLine: '*Y2h1bmtfc2l6Z*'
    SELECTION_16:
        CommandLine: '*AE8ALgBDAG8AbQBwAHIAZQBzAHMAaQBvAG4A*'
    SELECTION_17:
        CommandLine: '*kATwAuAEMAbwBtAHAAcgBlAHMAcwBpAG8Abg*'
    SELECTION_18:
        CommandLine: '*lPLkNvbXByZXNzaW9u*'
    SELECTION_19:
        CommandLine: '*SQBPAC4AQwBvAG0AcAByAGUAcwBzAGkAbwBuA*'
    SELECTION_2:
        Image: '*\powershell.exe'
    SELECTION_20:
        CommandLine: '*SU8uQ29tcHJlc3Npb2*'
    SELECTION_21:
        CommandLine: '*Ty5Db21wcmVzc2lvb*'
    SELECTION_22:
        CommandLine: '*AE8ALgBNAGUAbQBvAHIAeQBTAHQAcgBlAGEAbQ*'
    SELECTION_23:
        CommandLine: '*kATwAuAE0AZQBtAG8AcgB5AFMAdAByAGUAYQBtA*'
    SELECTION_24:
        CommandLine: '*lPLk1lbW9yeVN0cmVhb*'
    SELECTION_25:
        CommandLine: '*SQBPAC4ATQBlAG0AbwByAHkAUwB0AHIAZQBhAG0A*'
    SELECTION_26:
        CommandLine: '*SU8uTWVtb3J5U3RyZWFt*'
    SELECTION_27:
        CommandLine: '*Ty5NZW1vcnlTdHJlYW*'
    SELECTION_28:
        CommandLine: '*4ARwBlAHQAQwBoAHUAbgBrA*'
    SELECTION_29:
        CommandLine: '*5HZXRDaHVua*'
    SELECTION_3:
        CommandLine: '* hidden *'
    SELECTION_30:
        CommandLine: '*AEcAZQB0AEMAaAB1AG4Aaw*'
    SELECTION_31:
        CommandLine: '*LgBHAGUAdABDAGgAdQBuAGsA*'
    SELECTION_32:
        CommandLine: '*LkdldENodW5r*'
    SELECTION_33:
        CommandLine: '*R2V0Q2h1bm*'
    SELECTION_34:
        CommandLine: '*AEgAUgBFAEEARABfAEkATgBGAE8ANgA0A*'
    SELECTION_35:
        CommandLine: '*QASABSAEUAQQBEAF8ASQBOAEYATwA2ADQA*'
    SELECTION_36:
        CommandLine: '*RIUkVBRF9JTkZPNj*'
    SELECTION_37:
        CommandLine: '*SFJFQURfSU5GTzY0*'
    SELECTION_38:
        CommandLine: '*VABIAFIARQBBAEQAXwBJAE4ARgBPADYANA*'
    SELECTION_39:
        CommandLine: '*VEhSRUFEX0lORk82N*'
    SELECTION_4:
        CommandLine: '*AGkAdABzAGEAZABtAGkAbgAgAC8AdAByAGEAbgBzAGYAZQByA*'
    SELECTION_40:
        CommandLine: '*AHIAZQBhAHQAZQBSAGUAbQBvAHQAZQBUAGgAcgBlAGEAZA*'
    SELECTION_41:
        CommandLine: '*cmVhdGVSZW1vdGVUaHJlYW*'
    SELECTION_42:
        CommandLine: '*MAcgBlAGEAdABlAFIAZQBtAG8AdABlAFQAaAByAGUAYQBkA*'
    SELECTION_43:
        CommandLine: '*NyZWF0ZVJlbW90ZVRocmVhZ*'
    SELECTION_44:
        CommandLine: '*Q3JlYXRlUmVtb3RlVGhyZWFk*'
    SELECTION_45:
        CommandLine: '*QwByAGUAYQB0AGUAUgBlAG0AbwB0AGUAVABoAHIAZQBhAGQA*'
    SELECTION_46:
        CommandLine: '*0AZQBtAG0AbwB2AGUA*'
    SELECTION_47:
        CommandLine: '*1lbW1vdm*'
    SELECTION_48:
        CommandLine: '*AGUAbQBtAG8AdgBlA*'
    SELECTION_49:
        CommandLine: '*bQBlAG0AbQBvAHYAZQ*'
    SELECTION_5:
        CommandLine: '*aXRzYWRtaW4gL3RyYW5zZmVy*'
    SELECTION_50:
        CommandLine: '*bWVtbW92Z*'
    SELECTION_51:
        CommandLine: '*ZW1tb3Zl*'
    SELECTION_6:
        CommandLine: '*IAaQB0AHMAYQBkAG0AaQBuACAALwB0AHIAYQBuAHMAZgBlAHIA*'
    SELECTION_7:
        CommandLine: '*JpdHNhZG1pbiAvdHJhbnNmZX*'
    SELECTION_8:
        CommandLine: '*YgBpAHQAcwBhAGQAbQBpAG4AIAAvAHQAcgBhAG4AcwBmAGUAcg*'
    SELECTION_9:
        CommandLine: '*Yml0c2FkbWluIC90cmFuc2Zlc*'
    condition: (SELECTION_1 and SELECTION_2 and SELECTION_3 and (SELECTION_4 or SELECTION_5
        or SELECTION_6 or SELECTION_7 or SELECTION_8 or SELECTION_9 or SELECTION_10
        or SELECTION_11 or SELECTION_12 or SELECTION_13 or SELECTION_14 or SELECTION_15
        or SELECTION_16 or SELECTION_17 or SELECTION_18 or SELECTION_19 or SELECTION_20
        or SELECTION_21 or SELECTION_22 or SELECTION_23 or SELECTION_24 or SELECTION_25
        or SELECTION_26 or SELECTION_27 or SELECTION_28 or SELECTION_29 or SELECTION_30
        or SELECTION_31 or SELECTION_32 or SELECTION_33 or SELECTION_34 or SELECTION_35
        or SELECTION_36 or SELECTION_37 or SELECTION_38 or SELECTION_39 or SELECTION_40
        or SELECTION_41 or SELECTION_42 or SELECTION_43 or SELECTION_44 or SELECTION_45
        or SELECTION_46 or SELECTION_47 or SELECTION_48 or SELECTION_49 or SELECTION_50
        or SELECTION_51))
falsepositives:
- Penetration tests
id: f26c6093-6f14-4b12-800f-0fcb46f5ffd0
level: high
logsource:
    category: process_creation
    product: windows
references:
- http://www.leeholmes.com/blog/2017/09/21/searching-for-content-in-base-64-strings/
status: experimental
tags:
- attack.execution
- attack.t1059.001
- attack.t1086
yml_filename: win_susp_powershell_hidden_b64_cmd.yml
yml_path: /Users/user/Documents/YamatoSecurity/sigma/rules/windows/process_creation