Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9a7f4f00d77b88a…

MALICIOUS

PDF

226.1 KB Created: 2014-03-14 13:13:58 +00:00 Authoring application: Microsoft® Excel® 2010 First seen: 2015-09-16
MD5: 437a37127182054c3a0a80a4ac2d8ed0 SHA-1: 83dbde7c23221811624944eac2e532dce76a5606 SHA-256: a9a7f4f00d77b88a10e0ce6edaee474956a8ab2da1e8e92b946e3f9207b2b56c
576 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution T1105 Ingress Tool Transfer

The PDF contains embedded JavaScript that utilizes the `exportDataObject` function to launch an embedded executable disguised as 'Salaries.pdf'. This executable is then launched via `cmd.exe`, indicating a dropper functionality. The embedded executable is detected as a Windows executable, and the PDF itself exploits CVE-2010-1240 and CVE-2023-26369 related vulnerabilities to facilitate the execution.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 14

  • Adobe Reader Launch action command execution critical CVE exact CVE_2010_1240
    PDF uses the Adobe Reader/Acrobat Launch action pattern associated with CVE-2010-1240: cmd.exe is invoked with attacker-controlled parameters, paired with an embedded/exported payload.
  • TrueType bitmap font + active content — CVE-2023-26369 related high CVE related PDF_CVE_2023_26369_RELATED
    PDF embeds a TrueType font with bitmap tables (EBDT/sbix/CBDT) alongside exploit delivery indicators — CVE-2023-26369 exploits the sfac_GetSbitBitmap function in Adobe's libCoolType for arbitrary code execution. This CVE was actively exploited in the wild, but this rule does not validate the malformed EBLC/EBDT primitive.
  • ClamAV: Pdf.Tool.Agent-1388586 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Tool.Agent-1388586
  • Launch action critical PDF_LAUNCH
    PDF contains a /Launch action whose target is an executable, URL, or UNC path — can start an external application
  • Embedded Windows executable payload in PDF stream critical PDF_EMBEDDED_PE_PAYLOAD
    PDF stream bytes contain an embedded Windows executable with a verified PE header. Exploit chains often hide droppers inside ordinary streams rather than standard /EmbeddedFile attachments.
  • /Launch action target: cmd.exe critical PDF_LAUNCH_COMMAND
    PDF /Launch action specifies an executable target with parameters '/Q /C %HOMEDRIVE%&cd %HOMEPATH%&(if exist "Desktop\\Salaries.pdf" (cd "Desktop"' — references a known-dangerous executable (cmd, PowerShell, etc.).
  • Embedded attachment masquerades: declared document, content is windows-executable critical PDF_EMBEDDED_FILESPEC_CONTENT_MISMATCH
    An /EmbeddedFile attachment's declared filename extension or /Subtype MIME type contradicts the magic bytes of its decompressed content. The attachment is declared as a benign document or image but the bytes are an executable or executable-bearing archive. This is a deliberate deception used to hide droppers in PDF attachments and is a generic indicator of embed-and-drop weaponisation, independent of any specific CVE.
  • JavaScript action low 2 related findings PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • PDF JavaScript exploit cluster critical PDF_JS_EXPLOIT_CLUSTER
    PDF combines an executable JavaScript/action surface with exploit staging indicators such as eval/unescape/fromCharCode, XFA script content, or a related CVE pattern. Benign form JavaScript remains low-severity, but this correlated cluster is high-confidence malicious behavior.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • /Launch action paired with attachment-dropping JS API high PDF_LAUNCH_PLUS_DROPPER_JS
    PDF combines a /Launch action with a JavaScript API call that writes or opens an attached/external resource — the canonical shape of the CVE-2010-1240 /Launch + exportDataObject family. Benign PDFs do not pair these surfaces; the combination indicates a drop-and-execute chain regardless of the specific JS API knobs or /Launch target.
  • Suspicious extracted artifact medium 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 file low PDF_EMBEDDED
    PDF embeds a file attachment — could carry an executable or another weaponised document as a nested payload
  • 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 https://jill.cyberis.co.uk/beacone.php In extracted file (Salaries.pdf)
    • http://www.microsoft.com/typography/ctfontshttp://fontfabrik.comYouIn extracted file (font_00_sfnt_off000026e7.bin)
    • http://www.microsoft.com/typography/fonts/default.aspxIn extracted file (font_00_sfnt_off000026e7.bin)
    • http://crl.microsoft.com/pki/crl/products/MicCodSigPCA_08-31-2010.crl0ZIn extracted file (font_00_sfnt_off000026e7.bin)
    • http://www.microsoft.com/pki/certs/MicCodSigPCA_08-31-2010.crt0In extracted file (font_00_sfnt_off000026e7.bin)
    • http://crl.microsoft.com/pki/crl/products/MicrosoftTimeStampPCA.crl0XIn extracted file (font_00_sfnt_off000026e7.bin)
    • http://www.microsoft.com/pki/certs/MicrosoftTimeStampPCA.crt0In extracted file (font_00_sfnt_off000026e7.bin)
    • http://crl.microsoft.com/pki/crl/products/microsoftrootcert.crl0TIn extracted file (font_00_sfnt_off000026e7.bin)
    • http://www.microsoft.com/pki/certs/MicrosoftRootCert.crt0In extracted file (font_00_sfnt_off000026e7.bin)
    • http://www.microsoft.com/typographyIn extracted file (font_00_sfnt_off000026e7.bin)

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
Salaries.pdf pdf-embedded-file PDF EmbeddedFile object 337 at offset 0x2DFBC 88064 bytes
SHA-256: 8490446b23becbb4a450aab4fe3f708c8a8b8981e5887c2875fef25536c51b2d
Detection
ClamAV: No threats found
Obfuscation or payload: likely
actual_type=PE; declared_or_context_type=PDF; filename=Salaries.pdf; kind=pdf-embedded-file
javascript_obj0338_000.js pdf-javascript-stream PDF /JS object 338 at offset 0x382E1 57 bytes
SHA-256: a3448aafca766f05c4dd662a455724999aea0445a6a537ea0db05cd4d5b5c233
Preview script
First 1,000 lines of the extracted script
this.exportDataObject({ cName: "Salaries", nLaunch: 0 });
font_00_sfnt_off000026e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x26E7 181316 bytes
SHA-256: 3d11843ac085554974034f964f41910c24d1c6bacb0f24e44479fe795ccd9340
font_01_sfnt_off000173d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x173D0 179688 bytes
SHA-256: a66c2ddd024518f79d69c3a0a14c8b57b6574cef5efd464f4cee08c47c5ea71c