A Linux host was used to collect various system release files and kernel details, writing them into a single file under /tmp. What was the name of that output file?

DeviceFileEvents 
| where (ActionType == "FileCreated" or ActionType == "FileWritten")
| where FolderPath startswith "/tmp"
| where InitiatingProcessCommandLine has_any ("cat", "lsb_release", "uname", "release", "os-release", "kernel", ">", "/etc/")
| project TimeGenerated, FileName, FolderPath, InitiatingProcessCommandLine, OutputFile=strcat(FolderPath, "/", FileName)
| summarize Count=count(), ExampleCommand=any(InitiatingProcessCommandLine), FirstSeen=min(TimeGenerated) by OutputFile
| order by Count desc, FirstSeen asc
| take 10

DeviceFileEvents
| where FolderPath startswith "/tmp"
| summarize by FileName
| project FileName

let linux_devices = DeviceInfo
| where OSPlatform == "Linux"
| distinct DeviceId;
let release_rx = @"(?i)(/etc/(?:os-release|lsb-release|redhat-release|system-release)|/etc/issue|\blsb_release\b)";
let kernel_rx  = @"(?i)\b(?:uname\s+(?:-a|-r)|hostnamectl|/proc/version)\b";
DeviceProcessEvents
| where ActionType == "ProcessCreated"
| where DeviceId in (linux_devices)
// Extract an output path under /tmp written via redirection or tee
| extend OutputPath = coalesce(
    extract(@">>{0,1}\s*(/tmp/[^ \t|;&>]+)", 1, ProcessCommandLine),
    extract(@"\btee\b[^\r\n]*\s+(/tmp/[^ \t|;&>]+)", 1, ProcessCommandLine)
)
| where isnotempty(OutputPath)
| extend HasRelease = ProcessCommandLine matches regex release_rx
| extend HasKernel  = ProcessCommandLine matches regex kernel_rx
// Aggregate per device and output path to ensure both data types were written to the same file
| summarize FirstSeen=min(TimeGenerated), LastSeen=max(TimeGenerated), AnyRelease=any(HasRelease), AnyKernel=any(HasKernel), ExampleCmd=arg_max(TimeGenerated, ProcessCommandLine) by DeviceId, DeviceName, OutputPath
| where AnyRelease and AnyKernel
| extend OutputFile = extract(@"[^/]+$", 0, OutputPath)
| project LastSeen, DeviceName, OutputPath, OutputFile, ExampleCmd
| order by LastSeen desc

let keywords = dynamic(["release","os-release","lsb-release","issue","kernel","uname","version","system-release","sysinfo","osinfo","os_release"]);
let pathPrefix = "/tmp/";
let lastN = 50;
(
  DeviceFileEvents
  | where coalesce(TimeGenerated, Timestamp) >= ago(30d)
  | extend Time = coalesce(TimeGenerated, Timestamp)
  | extend InitiatingCmd = tolower(coalesce(InitiatingProcessCommandLine, ""))
  | where (isnotempty(FolderPath) and FolderPath startswith pathPrefix)
        or (isnotempty(FileName) and tolower(FileName) has_any (keywords))
        or (InitiatingCmd has_any (keywords))
  | extend FullPath = iff(isnotempty(FolderPath), iff(FolderPath endswith "/", strcat(FolderPath, FileName), strcat(FolderPath, "/", FileName)), FileName)
  | project Time, DeviceName, Table = "DeviceFileEvents", FullPath, FileName, FolderPath, InitiatingProcessFileName, InitiatingCmd, ActionType, FileSize, MD5, SHA1, SHA256
)
| union (
  DeviceEvents
  | where coalesce(TimeGenerated, Timestamp) >= ago(30d)
  | extend Time = coalesce(TimeGenerated, Timestamp)
  | extend InitiatingCmd = tolower(coalesce(InitiatingProcessCommandLine, ""))
  | where (isnotempty(FolderPath) and FolderPath startswith pathPrefix)
        or (isnotempty(FileName) and tolower(FileName) has_any (keywords))
        or (InitiatingCmd has_any (keywords))
  | extend FullPath = iff(isnotempty(FolderPath), iff(FolderPath endswith "/", strcat(FolderPath, FileName), strcat(FolderPath, "/", FileName)), FileName)
  | project Time, DeviceName, Table = "DeviceEvents", FullPath, FileName, FolderPath, InitiatingProcessFileName, InitiatingCmd, ActionType, FileSize, MD5, SHA1, SHA256
)
| union (
  DeviceProcessEvents
  | where coalesce(TimeGenerated, Timestamp) >= ago(30d)
  | extend Time = coalesce(TimeGenerated, Timestamp)
  | extend InitiatingCmd = tolower(coalesce(ProcessCommandLine, InitiatingProcessCommandLine, ""))
  | where (isnotempty(FolderPath) and FolderPath startswith pathPrefix)
        or (isnotempty(FileName) and tolower(FileName) has_any (keywords))
        or (InitiatingCmd has_any (keywords))
  | extend FullPath = iff(isnotempty(FolderPath), iff(FolderPath endswith "/", strcat(FolderPath, FileName), strcat(FolderPath, "/", FileName)), FileName)
  | project Time, DeviceName, Table = "DeviceProcessEvents", FullPath, FileName, FolderPath, InitiatingProcessFileName=InitiatingProcessFileName, InitiatingCmd, ActionType, FileSize, MD5, SHA1, SHA256
)
| summarize arg_max(Time, *) by FullPath, DeviceName
| order by Time desc
| take lastN

// Find processes that read common system release/kernel files and write an aggregated file under /tmp
let proc = DeviceProcessEvents
| extend cmd = tolower(tostring(ProcessCommandLine)), icmd = tolower(tostring(InitiatingProcessCommandLine))
| where isnotempty(cmd) or isnotempty(icmd)
// Look for reads of common Linux release/kernel info
| where (
    (cmd contains "/etc/" and cmd contains "release")
    or cmd contains "/proc/version"
    or cmd contains "boot/config"
    or cmd contains "os-release"
    or cmd contains "uname"
    or cmd contains "dmesg"
    or (icmd contains "/etc/" and icmd contains "release")
    or icmd contains "/proc/version"
    or icmd contains "boot/config"
    or icmd contains "os-release"
    or icmd contains "uname"
    or icmd contains "dmesg"
)
// And also evidence of writing to /tmp (redirection, tee, cp, mv, or explicit /tmp path)
| where (
    cmd contains "/tmp/" or icmd contains "/tmp/"
    or cmd matches regex @"(>\s*/tmp/|>>\s*/tmp/|1>\s*/tmp/)"
    or cmd matches regex @"(\btee\b|\scp\b|\smv\b).*?/tmp/\S+"
    or icmd matches regex @"(>\s*/tmp/|>>\s*/tmp/|1>\s*/tmp/)"
    or icmd matches regex @"(\btee\b|\scp\b|\smv\b).*?/tmp/\S+"
)
| extend outpath = coalesce(
    extract("(/tmp/\\S+)", 1, cmd),
    extract("(/tmp/\\S+)", 1, icmd)
)
| project TimeGenerated, DeviceName, ProcessId, FileName, FolderPath, outpath, ProcessCommandLine=ProcessCommandLine, InitiatingProcessCommandLine=InitiatingProcessCommandLine
;

let fileEvents = DeviceFileEvents
| where FolderPath has "/tmp" or FileName has "/tmp" or FolderPath endswith "/tmp"
| extend outpath = case(
    FileName has "/tmp/", FileName,
    FolderPath endswith "/", strcat(FolderPath, FileName),
    FolderPath contains "/tmp", strcat(FolderPath, "/", FileName),
    strcat(FolderPath, "/", FileName)
)
| project TimeGenerated, DeviceName, FileName, FolderPath, ActionType, outpath, InitiatingProcessCommandLine
;

// Combine and show recent matches and a top summary of candidate /tmp file names
proc
| union fileEvents
| summarize hits = count(), any_Time = max(TimeGenerated) by outpath, DeviceName
| where isnotempty(outpath)
| order by hits desc, any_Time desc
| limit 20

// Uncomment below to see the raw recent events (limit 50)
// proc | union fileEvents | order by TimeGenerated desc | limit 50

DeviceFileEvents
| where FolderPath startswith "/tmp"
| where ActionType == "FileCreated"
| join kind=inner (
    DeviceInfo
    | where OSPlatform contains "Linux"
) on DeviceId
| project FileName, FolderPath, DeviceName, Timestamp
| order by Timestamp desc

DeviceFileEvents
| where FolderPath startswith '/tmp/'
| where ActionType == 'FileCreated'  // Adjust based on actual ActionType values if needed
| project FileName, InitiatingProcessCommandLine, Timestamp
| order by Timestamp desc
| take 10  // Limit to top 10 recent events for review

// Filter to Linux devices
let LinuxDevices = DeviceInfo
| where OSPlatform =~ "Linux"
| distinct DeviceId;

LinuxDevices
| join kind=inner (
    DeviceProcessEvents
    // Look for process events where the command likely collects system release or kernel details
    | where ProcessCommandLine has_any ("/etc/", "release", "uname")
    // Look for a redirect to a file under /tmp
    | where ProcessCommandLine matches regex @"[>]{1,2}\s*/tmp/"
    // Parse out the output file name
    | parse kind=regex ProcessCommandLine with @".*[>]{1,2}\s*(/tmp/[^\s]+).*" outputFile
    | project TimeGenerated, DeviceId, DeviceName, ProcessCommandLine, outputFile
) on DeviceId
| project TimeGenerated, DeviceName, ProcessCommandLine, outputFile
| order by TimeGenerated desc

// Join with DeviceInfo to find only devices running Linux
DeviceProcessEvents
| join kind=inner (
    DeviceInfo
    | where OSPlatform == "Linux"
    | distinct DeviceId
) on DeviceId
// Look for commands referencing release files or kernel details often seen on Linux
| where ProcessCommandLine has_any("release", "kernel", "uname", "lsb_release", "os-release", "version")
// Also ensure the command line references /tmp
| where ProcessCommandLine has "/tmp/"
// Use regex to extract the portion of the file name under /tmp
| extend OutputFile = extract(@"/tmp/([^ ]+)", 1, ProcessCommandLine)
// Select relevant fields
| project TimeGenerated, DeviceName, ProcessCommandLine, OutputFile
| order by TimeGenerated desc

// ----------------------------------------------
// Linux host – identify file into which release / kernel information was aggregated
// ----------------------------------------------
let linux_devices = DeviceInfo
    | where OSPlatform =~ "Linux"
    | project DeviceId;
DeviceProcessEvents
| where DeviceId in (linux_devices)
// command must reference typical OS / kernel info sources…
| where ProcessCommandLine has_any ("/etc/os-release", "/etc/lsb-release", "/etc/redhat-release", "/etc/system-release", "/proc/version", "lsb_release", "uname", "hostnamectl")
// …and redirect that output to /tmp (either ">" or ">>")
| where ProcessCommandLine contains "/tmp/" and ProcessCommandLine has ">"
// extract the redirected file path that sits after the > or >> token
| extend OutputFilePath = tostring(extract(@">+\s*(/tmp/[^\s>]+)", 1, ProcessCommandLine))
| where isnotempty(OutputFilePath)
// pull out just the file name portion
| extend OutputFileName = tostring(split(OutputFilePath, "/")[-1])
// show when we first / last saw it, per host (optional but useful)
| summarize FirstSeen=min(TimeGenerated), LastSeen=max(TimeGenerated) by DeviceName, OutputFilePath, OutputFileName
| order by LastSeen desc

DeviceProcessEvents
| where InitiatingProcessCommandLine contains "> /tmp/"
// Focus on Linux system collection commands by filtering for likely keywords
| where InitiatingProcessCommandLine contains "release" or InitiatingProcessCommandLine contains "kernel"
| extend OutputFile = extract(@">\s*(/tmp/\S+)", 1, InitiatingProcessCommandLine)
| where isnotempty(OutputFile)
| project TimeGenerated, DeviceName, InitiatingProcessCommandLine, OutputFile
| order by TimeGenerated desc
| limit 100

let linuxDevices = DeviceInfo
| where OSPlatform == "Linux"
| distinct DeviceId;
DeviceProcessEvents
| where TimeGenerated between (startofday(ago(7d)) .. now()) // time range will be set by the portal
| where DeviceId in (linuxDevices)
| where ProcessCommandLine contains ">" and ProcessCommandLine contains "/tmp/"
| extend OutputFile = extract(@">\s*\/tmp\/(?<filename>[^\s]+)", 1, ProcessCommandLine)
| where isnotempty(OutputFile)
| summarize Count = count() by OutputFile
| sort by Count desc

// Identify Linux devices
let LinuxDevices = DeviceInfo
| where OSPlatform has "Linux"
| distinct DeviceId;

// Find process executions that redirect output into /tmp
DeviceProcessEvents
| where DeviceId in (LinuxDevices)
// Look for redirection operators writing to /tmp
| where ProcessCommandLine matches regex @"[>]{1,2}\s*/tmp/"
| project TimeGenerated, DeviceName, ProcessCommandLine
// Extract the target filename under /tmp
| extend OutputFile = extract(@"[>]{1,2}\s*(/tmp/\S+)", 1, ProcessCommandLine)
// Return distinct file names and context
| summarize arg_max(TimeGenerated, *) by OutputFile
| project TimeGenerated, DeviceName, OutputFile, ProcessCommandLine