Malicious Office (OLE) — malware analysis report

Static analysis result for SHA-256 e4a33c7818a9cf9c…

MALICIOUS

Office (OLE)

343.0 KB Created: 2015-06-05 18:17:20
MD5: 4942f8e35bde6d5e85139c848a8285c0 SHA-1: 7ae9a3b43f191fdc818cbbdcaa60b475e64e3b9e SHA-256: e4a33c7818a9cf9ceb3ac44b0138c1bbd40f288bdaf8839add5b42e74a238ade
508 Risk Score

Malware Insights

MITRE ATT&CK
T1059.001 PowerShell T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The sample contains a Workbook_Open VBA macro that attempts to execute an embedded PE executable. The macro uses ShellExecuteA to run 'rundll32' with arguments that point to a DLL named 'omsh.dll' located in the user's temporary directory. This DLL is likely the embedded executable, and the macro's intent is to download and execute a second-stage payload. The 'SE_CLIPBOARD_COMMAND_LURE' heuristic further indicates that the document prompts the user to interact with the command line.

Heuristics 15

  • Embedded PE executable critical OLE_EMBEDDED_EXE
    MZ/PE header found inside document — possible embedded executable
  • Reference to CreateProcess API high SC_STR_CREATEPROCESS
    Reference to CreateProcess API
  • Reference to ShellExecute API high SC_STR_SHELLEXEC
    Reference to ShellExecute API
  • Reference to LoadLibrary API high SC_STR_LOADLIBRARY
    Reference to LoadLibrary API
  • Reference to GetProcAddress API high SC_STR_GETPROCADDRESS
    Reference to GetProcAddress API
  • Workbook_Open macro high OLE_VBA_WBOPEN
    Workbook_Open macro
  • Ole10Native package carries executable/script file type high OFFICE_PACKAGE_RISKY_FILE
    OLE Package displayName or fullPath ends in an executable or script-capable extension. Even without UI extension spoofing, embedding a runnable payload inside an Office document is a high-risk delivery pattern.
  • 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.
  • Clipboard command execution lure high SE_CLIPBOARD_COMMAND_LURE
    Document tells the user to copy or paste clipboard content into Run, PowerShell, cmd, or another shell-like execution context
  • Suspicious extracted artifact high 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.
  • NOP-equivalent sled detected medium SC_NOP_EQUIV_SLED
    Long run of 0x40 bytes
  • Reference to VirtualAlloc API medium SC_STR_VIRTUALALLOC
    Reference to VirtualAlloc API
  • Reference to VirtualProtect API medium SC_STR_VIRTUALPROTECT
    Reference to VirtualProtect API
  • VBA macros detected medium OLE_VBA_MACROS
    Document contains VBA macro code
  • Environ() call (env variable access) low OLE_VBA_ENVIRON
    Environ() call (env variable access)

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
d2233606c870b49b0cb48a4294912a57af28cda30621f31fbca9eaa7c4cdc249
vba-macro oletools.olevba.extract_macros (decoded VBA source) 2074 bytes
embedded_office_00001265.exe
1a44b554ebf126585d39f7e22fc05476258863d02ea7ceab639af13b9d40d510
embedded-pe Office MZ+PE at offset 0x1265 346523 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved macro source contains an auto-exec entry point and execution/download terms.
ole10native_00.bin
9d3027d937dbbc4b6c7d85c4c82e08654d1bc7c2787c7c4e9d8a4cbf11356580
ole-package OLE Ole10Native stream: MBD0132A5F4/Ole10Native 205073 bytes