Malicious Office (OOXML) / .XLSX — malware analysis report

Static analysis result for SHA-256 a9dbbc729415528b…

MALICIOUS

Office (OOXML) / .XLSX

44.9 KB Created: 2020-02-01 18:28:07 UTC Authoring application: Microsoft Excel 12.0000
MD5: 22c72b1578c3dcccd40da5b0ff7cd288 SHA-1: d8b97bc4e2a3c9d7f02ec91864d180ecf69bcc2e SHA-256: a9dbbc729415528b9f09296c293c089542caed352baff9de8e497688a4279c07
500 Risk Score

Malware Insights

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

The file is an XLSX document containing a VBA macro with an Auto_Open function. This macro utilizes WScript.Shell and CreateObject to execute a Base64-decoded shell command, which downloads a PE file from the URL http://185.244.39.251/GBA7KYzWIwqwxds.exe. The presence of an Equation Editor OLE object and ClamAV detections further indicate malicious intent.

Heuristics 11

  • Equation Editor OLE object high CVE related OLE_EQUATION_EDITOR
    Embedded OLE object xl/embeddings/oleObject3.bin contains the Equation Editor CLSID, the legacy component exploited by CVE-2017-11882, CVE-2018-0802, and CVE-2018-0798.
  • Shell() call in VBA critical OLE_VBA_SHELL
    Shell() call in VBA
  • WScript.Shell usage critical OLE_VBA_WSCRIPT
    WScript.Shell usage
  • VBA Base64-decoded Shell command stager critical OLE_VBA_BASE64_SHELL_COMMAND_STAGER
    VBA auto-exec macro decodes Base64 string literals into command or script-launch text and executes the result with Shell. This catches cmd/cscript/PowerShell/VBS launchers hidden from plain keyword matching.
    URL http://185.244.39.251/GBA7KYzWIwqwxds.exe
  • ClamAV: Xls.Dropper.Agent-7763659-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Xls.Dropper.Agent-7763659-0
  • ClamAV detection on extracted artifact critical EXTRACTED_FILE_CLAMAV
    ClamAV flagged at least one file extracted from inside this sample. Even when the wrapping document carries no AV detection of its own, a hit on the carved artifact is a strong indicator the sample is a delivery vehicle.
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • CreateObject call high OLE_VBA_CREATEOBJ
    CreateObject call
  • 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.
  • VBA project inside OOXML medium OOXML_VBA
    Document contains vbaProject.bin — VBA macros present
  • Embedded OLE object medium OOXML_OLE_OBJECT
    Document contains an embedded OLE object

Extracted artifacts 9

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas
6819ce8cdf06fa27bfec64f818b1307d30e9c11e47ee9edfb64ff0806df6a71c		 vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 20783 bytes
Detection
ClamAV: No threats found
Obfuscation or payload: likely
Carved artifact contains 1 shell/COM execution token(s). Carved artifact contains 1 long base64-like blob(s). Carved macro source contains an auto-exec entry point and execution/download terms.
ooxml_oleobject_00.bin
d929f2e2068be842b0e472c19a97767602b62ad6a3068165784369516df7fbc9		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject1.bin 3584 bytes
ooxml_oleobject_00_ole10native_00.bin
d81ab8f37617b70cef788a949471ba956979b76c88c3817ceee0f1d8ebf87516		 ole-package OOXML xl/embeddings/oleObject1.bin Ole10Native stream: Ole10Native 978 bytes
ooxml_oleobject_01.bin
c3c9f81a73d977e07d7ac7a860ff7b2bb8905c77693b718c35f671fb909c8f5d		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject3.bin 5936 bytes
ooxml_oleobject_02.bin
59f98690909bf69a7e661526edb5c0a199a30b57a14f3595d73311cbc3581d84		 ooxml-ole-object OOXML embedded OLE part: xl/embeddings/oleObject2.bin 12288 bytes
ooxml_oleobject_02_ole10native_00.bin
157e18145d85b07504f819a4edf9340cb36d7e907f507b22bbd404f165740b00		 ole-package OOXML xl/embeddings/oleObject2.bin Ole10Native stream: Ole10Native 9239 bytes
ooxml_oleobject_03.bin
a90f7575d6dded184aee92cf563545808c903b4000fa1c5100fcb9b9cc935029		 ooxml-ole-object OOXML embedded OLE part: xl/vbaProject.bin 39936 bytes
Detection
ClamAV: Xls.Dropper.Agent-7763659-0
Obfuscation or payload: unlikely
emf_00.emf
979dde2aed02f077c16ae53546c6df9eed40e8386d6db6fc36aee9f966d2cb82		 ooxml-emf OOXML EMF part: xl/media/image1.emf 4968 bytes
emf_01.emf
4d4d1e7b04c99dcb8e885915068ad6f74cc2333e91580cdae5ccaa00c427247f		 ooxml-emf OOXML EMF part: xl/media/image2.emf 1536 bytes

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