Malicious PDF — malware analysis report

Static analysis result for SHA-256 4256cb7c8cd6263a…

MALICIOUS

PDF

76.5 KB Created: 2021-09-13 12:44:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 2849e39de37ab18760f4e669bba98ae8 SHA-1: ad76dbf4eff6b0a35741964e631c6c7509fd021f SHA-256: 4256cb7c8cd6263aa970b34e9aea27cafb50762a7669f2bf242582e7e802d138
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs pointing to a link farm, a common tactic for phishing or distributing further malicious content. While no scripts were explicitly extracted, the PDF structure and the presence of external URIs suggest it is designed to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://simpangkanan.com/contents/files/bimatudapuxufopukuninu.pdf In PDF document text
    • http://www.facyt.com.ar/ckfinder/userfiles/files/71878066753.pdfIn PDF document text
    • https://ocw.tw/uploads/files/46523479340.pdfIn PDF document text
    • http://weilandvloeren.nl/fckimages/62113563147.pdfIn PDF document text
    • http://www.aamuhsv-madisonalumni.org/files/files/80763242618.pdfIn PDF document text
    • https://vico-inmobiliaria.com/ckfinder/userfiles/files/11641388048.pdfIn PDF document text
    • http://kelt.pl/userfiles/file/45479655538.pdfIn PDF document text
    • https://betenenergy.com/sites/default/files/file/89523497845.pdfIn PDF document text
    • http://koala-al.com/d/files/64060797193.pdfIn PDF document text
    • http://winteringlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/rufatewuvokapitiniz.pdfIn PDF document text
    • https://ketex.com/trcgp/ckfinder/userfiles/files/zuwanef.pdfIn PDF document text
    • http://heorungminhphat.com/luutru/files/zupadazezenuzu.pdfIn PDF document text
    • http://yds-wcv.jp/free_images/files/33448571215.pdfIn PDF document text
    • https://minhgianggroup.vn/upload/files/69064815737.pdfIn PDF document text
    • http://tonyprins.nl/images/uploads/file/92244793854.pdfIn PDF document text
    • https://ntiverification.com/userfiles/file/42097469040.pdfIn PDF document text
    • https://alley.52886.tw/uploads/files/73850846412.pdfIn PDF document text
    • http://technocom.pl/editor/file/64920415930.pdfIn PDF document text
    • http://chernogolovka.inhome360.ru/admin/ckfinder/userfiles/files/jopisoga.pdfIn PDF document text
    • http://www.phonefixcomo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613526b05cca3---webesavudezipugazop.pdfIn PDF document text
    • http://parquet-cortes.fr/data/Files/64124259675.pdfIn PDF document text
    • http://taxicityplus.ru/userfiles/file/73268247857.pdfIn PDF document text
    • http://tecsun-moscow.ru/docs/file/suxavezus.pdfIn PDF document text
    • https://textosolutionslinguistiques.com/upload/editor/file/63302376144.pdfIn PDF document text
    • http://puntolinea.org/userfiles/files/zobosuvizalit.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=season+12+episode+6+supernaturalPDF 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_off0000c2f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2F9 10900 bytes
SHA-256: 6e54a6f5ecf943598ac7b1fda6723b37b77304fd414bd372c145c9379fbfb432
font_01_sfnt_off0000dc5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC5B 18588 bytes
SHA-256: 560c8d26ccdccf60b5982a6cb9e0b0daf1b5783f543885c5595fb0d878744a08
font_02_sfnt_off00010c4b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C4B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1