What is api-ms-win-crt-stdio-l1-1-0.dll?

api-ms-win-crt-stdio-l1-1-0.dll is part of Microsoft® Windows® Operating System and developed by Microsoft Corporation according to the api-ms-win-crt-stdio-l1-1-0.dll version information.

api-ms-win-crt-stdio-l1-1-0.dll's description is "ApiSet Stub DLL"

api-ms-win-crt-stdio-l1-1-0.dll is digitally signed by Microsoft Corporation.

api-ms-win-crt-stdio-l1-1-0.dll is usually located in the 'C:\Program Files\Mozilla Firefox\' folder.

None of the anti-virus scanners at VirusTotal reports anything malicious about api-ms-win-crt-stdio-l1-1-0.dll.

If you have additional information about the file, please share it with the FreeFixer users by posting a comment at the bottom of this page.

VirusTotal report

None of the 62 anti-virus programs at VirusTotal detected the api-ms-win-crt-stdio-l1-1-0.dll file.

Sandbox Report

The following information was gathered by executing the file inside Cuckoo Sandbox.

Summary

Successfully executed process in sandbox.

Summary

{
    "dll_loaded": [
        "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll"
    ],
    "file_opened": [
        "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll"
    ],
    "command_line": [
        "\"C:\\Windows\\System32\\rundll32.exe\" C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll,DllMain"
    ],
    "file_exists": [
        "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll",
        "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll.manifest"
    ],
    "file_read": [
        "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll"
    ],
    "regkey_read": [
        "HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\GRE_Initialize\\DisableMetaFiles"
    ]
}

Generic

[
    {
        "process_path": "C:\\Windows\\System32\\rundll32.exe",
        "process_name": "rundll32.exe",
        "pid": 2336,
        "summary": {
            "file_exists": [
                "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll",
                "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll.manifest"
            ],
            "regkey_read": [
                "HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\GRE_Initialize\\DisableMetaFiles"
            ],
            "dll_loaded": [
                "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll"
            ]
        },
        "first_seen": 1607464385.921875,
        "ppid": 2740
    },
    {
        "process_path": "C:\\Windows\\SysWOW64\\rundll32.exe",
        "process_name": "rundll32.exe",
        "pid": 2740,
        "summary": {
            "dll_loaded": [
                "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll"
            ],
            "file_opened": [
                "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll"
            ],
            "command_line": [
                "\"C:\\Windows\\System32\\rundll32.exe\" C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll,DllMain"
            ],
            "file_exists": [
                "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll",
                "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll.manifest"
            ],
            "file_read": [
                "C:\\Users\\cuck\\AppData\\Local\\Temp\\0189cbd84dea035763a7e52225e0f1a7dcec402734885413add324bffe688577.bin.dll"
            ],
            "regkey_read": [
                "HKEY_LOCAL_MACHINE\\SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\GRE_Initialize\\DisableMetaFiles"
            ]
        },
        "first_seen": 1607464385.75,
        "ppid": 1664
    },
    {
        "process_path": "C:\\Windows\\System32\\lsass.exe",
        "process_name": "lsass.exe",
        "pid": 476,
        "summary": {},
        "first_seen": 1607464385.34375,
        "ppid": 376
    }
]

Signatures

[
    {
        "markcount": 1,
        "families": [],
        "description": "This executable has a PDB path",
        "severity": 1,
        "marks": [
            {
                "category": "pdb_path",
                "ioc": "api-ms-win-crt-stdio-l1-1-0.pdb",
                "type": "ioc",
                "description": null
            }
        ],
        "references": [],
        "name": "has_pdb"
    }
]

Yara

The Yara rules did not detect anything in the file.

Network

{
    "tls": [],
    "udp": [
        {
            "src": "192.168.56.101",
            "dst": "192.168.56.255",
            "offset": 662,
            "time": 6.219044923782349,
            "dport": 137,
            "sport": 137
        },
        {
            "src": "192.168.56.101",
            "dst": "224.0.0.252",
            "offset": 5442,
            "time": 6.155181884765625,
            "dport": 5355,
            "sport": 51001
        },
        {
            "src": "192.168.56.101",
            "dst": "224.0.0.252",
            "offset": 5770,
            "time": 4.165894985198975,
            "dport": 5355,
            "sport": 53595
        },
        {
            "src": "192.168.56.101",
            "dst": "224.0.0.252",
            "offset": 6098,
            "time": 6.162593841552734,
            "dport": 5355,
            "sport": 53848
        },
        {
            "src": "192.168.56.101",
            "dst": "224.0.0.252",
            "offset": 6426,
            "time": 4.666597843170166,
            "dport": 5355,
            "sport": 54255
        },
        {
            "src": "192.168.56.101",
            "dst": "224.0.0.252",
            "offset": 6754,
            "time": 3.0592658519744873,
            "dport": 5355,
            "sport": 55314
        },
        {
            "src": "192.168.56.101",
            "dst": "239.255.255.250",
            "offset": 7082,
            "time": 4.67953896522522,
            "dport": 1900,
            "sport": 1900
        },
        {
            "src": "192.168.56.101",
            "dst": "239.255.255.250",
            "offset": 18028,
            "time": 4.191568851470947,
            "dport": 3702,
            "sport": 49152
        },
        {
            "src": "192.168.56.101",
            "dst": "239.255.255.250",
            "offset": 26412,
            "time": 6.250438928604126,
            "dport": 1900,
            "sport": 53598
        }
    ],
    "dns_servers": [],
    "http": [],
    "icmp": [],
    "smtp": [],
    "tcp": [],
    "smtp_ex": [],
    "mitm": [],
    "hosts": [],
    "pcap_sha256": "135bd20cd2162dcb27cfafbffaec45d444b5d9fa08e5bb5dac87cd2890f42f6b",
    "dns": [],
    "http_ex": [],
    "domains": [],
    "dead_hosts": [],
    "sorted_pcap_sha256": "a02e219aac8164df08b317fb054bbafda0e1754aa5e81914621c33e660ce26cc",
    "irc": [],
    "https_ex": []
}

Screenshots

Folder name variants

api-ms-win-crt-stdio-l1-1-0.dll may also be located in other folders than C:\Program Files\Mozilla Firefox\. The most common variants are listed below:

• C:\Windows\WinSxS\amd64_avast.vc140.crt_fcc99ee6193ebbca_14.0.27012.0_none_5ca6eb17137337f1\

Malware or legitimate?

If you feel that you need more information to determine if your should keep this file or remove it, please read this guide.

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