Malicious PDF — malware analysis report

Static analysis result for SHA-256 88f8287af9765554…

MALICIOUS

PDF

93.5 KB Created: 2021-09-13 20:19:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 750ff9158efdea2a8987240928fa4a99 SHA-1: 82e4b79c69c5bb705bb7cbb20f1f816a61bd2f7d SHA-256: 88f8287af9765554a521b01e318e71d83f5394b803ce28db3f5fb9942293db1e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous external links, many pointing to disposable hosting, indicating a link farm or phishing lure. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards techniques used for initial access via spearphishing attachments, potentially leading to further exploitation.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

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 http://zkmeiqi.com/admin/ckfinder/upfile/files/nusepinuku.pdf In PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/48458529289.pdfIn PDF document text
    • http://szakkepzosiklos.hu/upload/file/29828497956.pdfIn PDF document text
    • http://szilasfood.hu/pic_upload/files/wutuvatuzarepipuvekezon.pdfIn PDF document text
    • http://classicalgardenstatues.com/uplds/file/pabejalepof.pdfIn PDF document text
    • https://alakharia.com/public_html/userfiles/file/81625100462.pdfIn PDF document text
    • http://albertopizzetti.it/userfiles/files/5527997402.pdfIn PDF document text
    • http://capriololaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/9384816969.pdfIn PDF document text
    • https://ost-fogging.com/upload/files/pivedan.pdfIn PDF document text
    • https://dragonexpressml.com/userfiles/files/99323607605.pdfIn PDF document text
    • http://helderlive.nl/ckfinder/userfiles/files/fipigorisijuvuwiditisuzel.pdfIn PDF document text
    • http://tysons-cafe.com/uploads/files/88282880240.pdfIn PDF document text
    • https://zakarpattya-tour.com/upload/14160602835.pdfIn PDF document text
    • http://charugarware.com/DEVELOPMENT/charu_garware/uploaded/userfiles/file/94497497355.pdfIn PDF document text
    • https://stopserv.ru/files/file/33177811112.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/161322f341190f---63630486957.pdfIn PDF document text
    • http://studiotecnicoforace.eu/userfiles/files/zowefomexerobe.pdfIn PDF document text
    • http://regcureguide.com/files/files/88693075279.pdfIn PDF document text
    • http://neoneophytou.com/ckfinder/userfiles/files/16340625461.pdfIn PDF document text
    • https://fpcofmacon.com/nbloom/fckuploads/file/zabitefijajuna.pdfIn PDF document text
    • https://gelblighting.com/userfiles/files/jafudunof.pdfIn PDF document text
    • http://kwiatmetal.pl/userfiles/file/5884577127.pdfIn PDF document text
    • https://www.agcontraincendios.es/ckfinder/userfiles/files/wefatowumemajuzejofope.pdfIn PDF document text
    • https://aglogistics-bo.net/userfiles/file/76669685240.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=get+free+donuts+simpsons+tapped+outPDF 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_off00010499.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10499 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00011cb0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CB0 10752 bytes
SHA-256: 05293e91f5b4012310a7eb2261fd5e3c1ede3a6b49df08354305b95e0bb66d48
font_02_sfnt_off0001356d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1356D 19340 bytes
SHA-256: a83e1829d0dc1aa26d86a63404b1fb634484cf8f090ded8beb5bc5498bd69671