Malicious PDF — malware analysis report

Static analysis result for SHA-256 139bab737d7177b8…

MALICIOUS

PDF

80.8 KB Created: 2021-09-13 23:49:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c0914ae2f93df96e697b1c328790dc24 SHA-1: 5cec58190b959e8a6cea1d6f68110a62e8cf6ef1 SHA-256: 139bab737d7177b8eee7776a31d258e370bc6fad2da60f1f81cbc4d409a68d3c
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious content. The presence of a link farm on disposable hosting, coupled with numerous unknown URLs pointing to PDF files, strongly suggests a phishing or malware distribution attempt. Although no scripts were directly extracted, the PDF structure and URL patterns are consistent with malicious document delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • 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://ppfi-online.com/userfiles/file/97206098852.pdf In PDF document text
    • http://telekommarketing.com/firme_data/files/duzumituwulomopipemud.pdfIn PDF document text
    • http://2015.letnifestiwal.pl/ckfinder/userfiles/files/45099864009.pdfIn PDF document text
    • http://adanateknikservis.web.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613f18f3af3ba---42215570244.pdfIn PDF document text
    • http://jiin-torng.com/uploadfiles/20210906212345.pdfIn PDF document text
    • https://qamarapps.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dec95c4e0f---womexi.pdfIn PDF document text
    • http://kfnmsz.com/upfolder/e/files/20210903191715.pdfIn PDF document text
    • http://njxinbell.com/upload/files/62610814560.pdfIn PDF document text
    • https://foundationkuzmanov.com/files/10109483682.pdfIn PDF document text
    • https://officialbacknumber.org/editor_up/vobogigeliberabibo.pdfIn PDF document text
    • http://archiw.gbpopatowiec.pl/img/upload/files/wezal.pdfIn PDF document text
    • http://keitbg.com/images/files/demotofipomu.pdfIn PDF document text
    • http://sumtinathholidays.com/admin/uploadfiles/file/rizenepixajogitozevisiba.pdfIn PDF document text
    • http://studioingtassinari.eu/userfiles/files/61588181808.pdfIn PDF document text
    • http://sushiosushi.com/uploads/files/29686624735.pdfIn PDF document text
    • https://7foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/80960750226.pdfIn PDF document text
    • https://namkhoasaigon.vn/web/images/files/vevimop.pdfIn PDF document text
    • http://mjengo.org/FCKeditor/editor/filemanager/connectors/php/connector.php?Command=FileUpload&Type=File&CurrentFolder=%2Ffile/nixoloxide.pdfIn PDF document text
    • http://nationshield.ae/userfiles/files/55400826173.pdfIn PDF document text
    • http://novo-foto.ru/ckfinder/userfiles/files/24418320637.pdfIn PDF document text
    • https://apotekatia.ba/fajlovi/mexopo.pdfIn PDF document text
    • http://restokrat.info/userfiles/file/1816409273.pdfIn PDF document text
    • https://caror.hu/ckfinder/userfiles/files/61315658676.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=telstra+widgets+androidPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/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://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d7dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD7DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000efee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFEE 17900 bytes
SHA-256: 86c05f59a035830de513d74abdf5b599d80934d362f187ee1d674dc6df671de8
font_02_sfnt_off00011e2d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11E2D 10472 bytes
SHA-256: 5329ef0ba281c87271c9dd2f392a78a2265b62500670ba41b63ac5a3fa239a45