private/Test-MITRETechnique.ps1

<#
.SYNOPSIS
Tests whether a given MITRE ATT&CK® Technique ID is valid.
 
.DESCRIPTION
The Test-MITRETechnique function tests whether a given MITRE Technique ID is valid. It checks if the provided Technique ID exists in the list of valid techniques.
 
.PARAMETER TechniqueId
The TechniqueId parameter specifies the MITRE Technique ID to be tested. It is a mandatory parameter and must be a non-empty string.
 
.EXAMPLE
Test-MITRETechnique -TechniqueId "T1001"
Returns: True
 
.EXAMPLE
Test-MITRETechnique -TechniqueId "T2000"
Returns: False
 
.NOTES
© 2023 The MITRE Corporation. This work is reproduced and distributed with the permission of The MITRE Corporation."
#>

function Test-MITRETechnique {
    [CmdletBinding()]
    [OutputType([bool])]
    param (
        [Parameter(Mandatory, ValueFromPipeline, Position = 0)]
        [ValidateNotNullOrEmpty()]
        [string]$TechniqueId
    )

    process {
        $ValidTechniques = @(
            "T1001",
            "T1003",
            "T1005",
            "T1006",
            "T1007",
            "T1008",
            "T1010",
            "T1011",
            "T1012",
            "T1014",
            "T1016",
            "T1018",
            "T1020",
            "T1021",
            "T1025",
            "T1027",
            "T1029",
            "T1030",
            "T1033",
            "T1036",
            "T1037",
            "T1039",
            "T1040",
            "T1041",
            "T1046",
            "T1047",
            "T1048",
            "T1049",
            "T1052",
            "T1053",
            "T1055",
            "T1056",
            "T1057",
            "T1059",
            "T1068",
            "T1069",
            "T1070",
            "T1071",
            "T1072",
            "T1074",
            "T1078",
            "T1080",
            "T1082",
            "T1083",
            "T1087",
            "T1090",
            "T1091",
            "T1092",
            "T1095",
            "T1098",
            "T1102",
            "T1104",
            "T1105",
            "T1106",
            "T1110",
            "T1111",
            "T1112",
            "T1113",
            "T1114",
            "T1115",
            "T1119",
            "T1120",
            "T1123",
            "T1124",
            "T1125",
            "T1127",
            "T1129",
            "T1132",
            "T1133",
            "T1134",
            "T1135",
            "T1136",
            "T1137",
            "T1140",
            "T1176",
            "T1185",
            "T1187",
            "T1189",
            "T1190",
            "T1195",
            "T1197",
            "T1199",
            "T1200",
            "T1201",
            "T1202",
            "T1203",
            "T1204",
            "T1205",
            "T1207",
            "T1210",
            "T1211",
            "T1212",
            "T1213",
            "T1216",
            "T1217",
            "T1218",
            "T1219",
            "T1220",
            "T1221",
            "T1222",
            "T1480",
            "T1482",
            "T1484",
            "T1485",
            "T1486",
            "T1489",
            "T1490",
            "T1491",
            "T1495",
            "T1496",
            "T1497",
            "T1498",
            "T1499",
            "T1505",
            "T1518",
            "T1525",
            "T1526",
            "T1528",
            "T1529",
            "T1530",
            "T1531",
            "T1534",
            "T1535",
            "T1537",
            "T1538",
            "T1539",
            "T1542",
            "T1543",
            "T1546",
            "T1547",
            "T1548",
            "T1550",
            "T1552",
            "T1553",
            "T1554",
            "T1555",
            "T1556",
            "T1557",
            "T1558",
            "T1559",
            "T1560",
            "T1561",
            "T1562",
            "T1563",
            "T1564",
            "T1565",
            "T1566",
            "T1567",
            "T1568",
            "T1569",
            "T1570",
            "T1571",
            "T1572",
            "T1573",
            "T1574",
            "T1578",
            "T1580",
            "T1583",
            "T1584",
            "T1585",
            "T1586",
            "T1587",
            "T1588",
            "T1589",
            "T1590",
            "T1591",
            "T1592",
            "T1593",
            "T1594",
            "T1595",
            "T1596",
            "T1597",
            "T1598",
            "T1599",
            "T1600",
            "T1601",
            "T1602",
            "T1606",
            "T1608",
            "T1609",
            "T1610",
            "T1611",
            "T1612",
            "T1613",
            "T1614",
            "T1615",
            "T1619",
            "T1620",
            "T1621",
            "T1622",
            "T1647",
            "T1648",
            "T1649",
            "T1650",
            "T1651",
            "T1652",
            "T1653",
            "T1654",
            "T1656",
            "T1657",
            "T1659"
        )

        if ($TechniqueId -in $ValidTechniques) {
            return $true
        } else {
            return $false
        }
    }
}