Malicious Office (OLE) / .XLS — malware analysis report

Static analysis result for SHA-256 756555727f6fc4df…

MALICIOUS

Office (OLE) / .XLS

4.76 MB Created: 2006-11-08 15:21:05 Authoring application: Microsoft Excel First seen: 2023-01-26
MD5: 760aae55f42eb1a88aa2832360ffbcfe SHA-1: ea1266b19d9942675e02fb2559ec1d6b139ee37e SHA-256: 756555727f6fc4df2f382a955385f17005dbe3588b1b0fa25e6f47dff24a2b86
622 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1204.002 Malicious File T1059.003 Windows Command Shell T1105 Ingress Tool Transfer

The sample contains heavily obfuscated VBA macros, including Workbook_Open and Auto_Open events, which are designed to execute malicious code. Critical heuristics indicate the use of WScript.Shell and ShellExecute, along with an ActiveX event that launches a decoded Excel4 macro. This strongly suggests the macro's purpose is to download and execute a second-stage payload from one of the embedded URLs.

Heuristics 15

  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • VBA ActiveX event launches decoded Excel4 macro critical OLE_VBA_ACTIVEX_XLM_STAGER
    VBA code attached to an auto-firing ActiveX/UserForm control event (e.g. _Layout/_Change/_Painted) decodes a string with Replace/Split/Join/StrReverse/Chr and passes the recovered formula text to ExecuteExcel4Macro. This bridges VBA event activation into XLM formula execution to call Win32 APIs / drop payloads while evading AutoOpen and Shell keyword detection — a high-confidence macro stager, not a specific Office parser CVE.
  • 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.
  • x86 GetPC stub (CALL $+5; POP EBP) high SC_GETPC_CALL
    x86 GetPC stub (CALL $+5; POP EBP)
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • Reference to Windows Script Host high SC_STR_WSCRIPT
    Reference to Windows Script Host
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • Auto_Close macro high OLE_VBA_AUTOCLOSE
    Auto_Close macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • CallByName call high OLE_VBA_CALLBYNAME
    CallByName call
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code
  • 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://srcedit.pekori.jp/tool/share_e.txt
    • http://srcedit.pekori.jp/tool/share.txt
    • http://srcedit.pekori.jp/tool/method_e.txt
    • http://srcedit.pekori.jp/tool/method.txt
    • http://srcedit.pekori.jp/
    • http://news.yahoo.co.jp/

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
4555c2809b20018c0166b3943bd78759aa3f54fdf9c94a88a2d49c6f7c6e4c11		 vba-macro oletools.olevba.extract_macros (decoded VBA source) 8388608 bytes

Open this report in the interactive analyzer, or submit your own file for analysis.