Malicious PDF — malware analysis report

Static analysis result for SHA-256 d88bb9e56d70bf34…

MALICIOUS

PDF

226.7 KB Created: 2013-08-30 09:57:56 -02:00 Authoring application: PrimoPDF http://www.primopdf.com (via Nitro PDF PrimoPDF) First seen: 2013-10-08
MD5: 31071ba52c699ca1544880bdd69428b8 SHA-1: 75507da5119468412befb67a4a1b516a3d0026cc SHA-256: d88bb9e56d70bf3430a162e363b8205c249f4958b0fc871a16e198a3bce3e4d4
596 Risk Score

Malware Insights

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

The PDF file contains JavaScript that uses the exportDataObject function to launch cmd.exe, which in turn executes an embedded Windows executable disguised as 'yahoo.pdf'. This executable is detected by ClamAV as Win.Trojan.Swrort-5710536-0, indicating it's a malicious payload. The CVE-2010-1240 exploit is leveraged for command execution, and the embedded executable suggests an attempt to download and run a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9988

Heuristics 13

  • 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.
  • 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\\yahoo.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.
  • Suspicious extracted artifact critical 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.
  • /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.
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • JavaScript action low 1 related finding PDF_JAVASCRIPT
    PDF contains a /JavaScript action. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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.
  • 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 http://www.primopdf.com In PDF document text
    • http://www.primopdf.com)/Author(grafikaIn PDF document text
    • http://www.zeustech.net/Referenced by PDF JavaScript
    • http://]hostname[:port]/pathIn extracted file (yahoo.pdf)
    • tcp://127.0.0.1:4444In extracted file (yahoo.pdf)
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://ns.adobe.com/iX/1.0/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://www.apache.org/Referenced by PDF JavaScript

Related samples 8

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

Full JSON: related samples API

Extracted artifacts 6

Files carved from inside the sample during analysis.

FilenameKindSourceSize
yahoo.pdf pdf-embedded-file PDF EmbeddedFile object 67 at offset 0x2DA01 73802 bytes
SHA-256: 52b410bbe0252245babbc7cf819bea50d50a9b5bf121e5d42944f26c9873f533
Detection
ClamAV: Win.Trojan.Swrort-5710536-0
Obfuscation or payload: likely
actual_type=PE; declared_or_context_type=PDF; filename=yahoo.pdf; kind=pdf-embedded-file Static shellcode analysis recovered the Metasploit stager connect-back address: 127.0.0.1:4444 (reverse/x86, placeholder) Static shellcode analysis found candidate code region(s). Indicators: SC_PEB_ACCESS, SC_MSF_BIND, SC_PUSH_STRING Static shellcode analysis recovered API/import strings: kernel32.dll, advapi32.dll, KERNEL32.DLL, ADVAPI32.DLL, LoadLibraryA, GetProcAddress
javascript_obj0068_000.js pdf-javascript-stream PDF /JS object 68 at offset 0x38625 54 bytes
SHA-256: d035c3545dc580d1836caed0f14c04053ebb30fbd5187d5d3c92d881d1f008d2
Preview script
First 1,000 lines of the extracted script
this.exportDataObject({ cName: "yahoo", nLaunch: 0 });
stream_016_off00028929.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x28929 30560 bytes
SHA-256: a14c062ac59d61d020f348314bbda4ee56f09f88b5b06f23305c2be81caf0c93
font_00_sfnt_off0002665d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x2665D 25236 bytes
SHA-256: 3dbbdd4756746e7f4056c6848e08b170be4dc0cbff04ac7a02fa27c100cad280
font_01_cff_off000283c6.bin pdf-font-stream PDF embedded font (cff) at offset 0x283C6 1184 bytes
SHA-256: a39600588b38719a2d3219aa4f90b72f2f71156544e6abd6b505ddbb3be2020b
font_03_cff_off0002b666.bin pdf-font-stream PDF embedded font (cff) at offset 0x2B666 6594 bytes
SHA-256: 452dc947f974f80ab7f3f0d540adb55102b793fbf6333f1eb1c74208a6aab437

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