Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3526069fef51506…

MALICIOUS

PDF

77.2 KB Created: 2021-09-18 20:05:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 5b728dace206e4151ac2cc8eff950216 SHA-1: cdd33d4bdd3c42c31c644bb49fa20cf5b8f137a7 SHA-256: a3526069fef515069c5c09817e6d86a8e7aa06e333963190fa66e30ad1a13fd1
106 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to other PDF files on distinct domains, indicating a link farm or redirection scheme. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this is a non-clustered link farm on disposable hosting. While no scripts were explicitly extracted, the presence of external URIs and the nature of the links suggest a potential phishing or scam lure, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9757

Heuristics 5

  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://gesundezellen.com/neu/userfiles/file/31867548365.pdf In PDF document text
    • http://trumoi-khutrung.com/upload/files/32370364831.pdfIn PDF document text
    • http://soluzionebenessere.eu/userfiles/files/66808682738.pdfIn PDF document text
    • http://erimti.com/userfiles/file/kusijavuj.pdfIn PDF document text
    • https://rieker-consulting.eu/files/file/vadufimerug.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/48885316837.pdfIn PDF document text
    • http://conelser.hu/fck_uploads/file/nuxisadoragakiji.pdfIn PDF document text
    • http://alotercuman.com/ckfinder/userfiles/files/2403226739.pdfIn PDF document text
    • http://www.dogwoodagility.nl/ckfinder/userfiles/files/ziruwokajetodanozegur.pdfIn PDF document text
    • https://ehotelgateway.com/bot/ckfinder/uf/files/fofaripewivugepafovusaz.pdfIn PDF document text
    • https://valve-toho.com/userfiles/file/37196160407.pdfIn PDF document text
    • http://discoveryenglish.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612ff4aa941cd---rodolimap.pdfIn PDF document text
    • https://ciar.vn/uploads/image/files/xigariro.pdfIn PDF document text
    • http://ambulatorioveterinarioilghirlandaio.it/userfiles/files/47302442317.pdfIn PDF document text
    • http://volkshilfe-vlbg.at/images/content/files/nelokinixofevab.pdfIn PDF document text
    • http://hamyarsanatco.com/ckfinder/userfiles/files/kitexab.pdfIn PDF document text
    • http://www.emporiocaritaspisa.it/wordpress/wp-content/plugins/formcraft/file-upload/server/content/files/1613b2c2644d81---33183028819.pdfIn PDF document text
    • https://cleaner.pl/userfiles/file/ruxeveg.pdfIn PDF document text
    • http://gabinetpro.gabinetpro.pl/kosmetyczka/krakow/files/fafis.pdfIn PDF document text
    • http://video-cycling.de/files/file/zazageja.pdfIn PDF document text
    • http://coaching-scolaire.net/userfiles/file/tomoloduzubikade.pdfIn PDF document text
    • http://www.gamylai.vn/uploads/files/89295802064.pdfIn PDF document text
    • http://wellogo.in/userfiles/file///14386525105.pdfIn PDF document text
    • http://recrute.fr/files/files/vabaxugilesowa.pdfIn PDF document text
    • https://hohsingfiber.com/ufiles/files/42520850060.pdfIn PDF document text
    • http://ortopediaszombathely.hu/editor_up/97871792632.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/ngfLrbzwjls/uplcv?utm_term=inshot+filters+downloadPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b2f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2F9 10488 bytes
SHA-256: 2cedffc824ffbafa8422e89f98d7b90ced358fe166a38464cedc119237a14187
font_01_sfnt_off0000cac8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAC8 18572 bytes
SHA-256: ea22841c398f9e2a3659febf84102fc72e4e1f9af667528d3ef3811cab0eafac
font_02_sfnt_off0000e7e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7E7 15212 bytes
SHA-256: 8a7fdcaa88460c6041d23d4e6e8afd9ca3f8d3bcfb414926b61ab88d356833cd
font_03_sfnt_off00010e54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E54 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1