Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6e5796f4cf09e08…

MALICIOUS

PDF

92.6 KB Created: 2021-10-10 23:55:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-31
MD5: 7c4b2bc4b19721ea3cc421d37ba78e57 SHA-1: aa910ebac5d3bf9266b64feacc102417e3c922e5 SHA-256: f6e5796f4cf09e083ffe5ccde78a118581d3ccf4938d999c3745dc1c0a1d4d30
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to external domains, many of which are structured as link farms. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a non-clustered link farm on disposable hosting, suggesting an attempt to obscure the true malicious destination. While no scripts were explicitly extracted, the PDF structure and embedded URLs strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 https://allytemp.ru/uplcv?utm_term=photography+day+2020 PDF link annotation
    • https://apgr.eu/UserFiles/file/lojelujakitizo.pdfIn PDF document text
    • http://ptaki.info/imgekoprojekty/files/67653789140.pdfIn PDF document text
    • http://www.cottagegrad.ru/files/file/xarovubedenomuzotese.pdfIn PDF document text
    • http://akvarium-olbrecht.cz/upload/file/16576341954.pdfIn PDF document text
    • http://inspeq.eu/public/files/xazojibesuzixipugila.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615dacdad03f4---vigulikatidon.pdfIn PDF document text
    • http://duszek-lasu.pl/userfiles/file/32441426340.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/8f312e2f53b93c1653807342d9832463/81623988891.pdfIn PDF document text
    • http://opusbiz.kr/data/editor/file/150925070761318d2c5c301.pdfIn PDF document text
    • https://digitaldaya.com/imagenes/file/26588450388.pdfIn PDF document text
    • http://maasmartcity.com/userfiles/file/73764103819.pdfIn PDF document text
    • http://grgct.com/ckfinder/userfiles/files/dekomulagugezes.pdfIn PDF document text
    • http://vanharteyoga.nl/uploads/files/95955286966.pdfIn PDF document text
    • http://homesunshinepharma.com/upload/files/71822987858.pdfIn PDF document text
    • http://fanghsin.com/uploads/files/202109120611393518.pdfIn PDF document text
    • http://liceoadultos.juniorcollege.cl/userfiles/files/94456299041.pdfIn PDF document text
    • http://sun-tes.ru/files/file/jirezavazapojirixineb.pdfIn PDF document text
    • https://www.oalysa.cz/ckfinder/userfiles/files/19860826634.pdfIn PDF document text
    • http://afro-safari.com/upload/files/ruxotabafo.pdfIn PDF document text
    • https://eyescare.vn/app/webroot/upload/ckfinder/files/dajaguxedatudim.pdfIn PDF document text
    • https://www.baust.edu.bd/app/webroot/ckfinder/userfiles/files/59394354020.pdfIn PDF document text
    • http://mislenyiallatorvos.hu/userfiles/file/79530846223.pdfIn PDF document text
    • http://gernano.eu/gfx/userfiles/files/banapozumovifidowe.pdfIn PDF document text
    • https://shen-su.eu/gfx/userfiles/files/rogobodob.pdfIn PDF document text
    • 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_off0001059d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1059D 18328 bytes
SHA-256: d025112c82838b1e6c189c20dd1534ddab5f3dc75bee0e56f32495c6512962fa
font_01_sfnt_off00013498.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13498 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00014caf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14CAF 10488 bytes
SHA-256: 87a3d3b35662be47b4592f2dad37a66c62b6e8edca954dd3d4539e0d659e7ad3