Malicious PDF — malware analysis report

Static analysis result for SHA-256 5158e837eaea792b…

MALICIOUS

PDF

71.5 KB Created: 2021-09-14 12:58:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 24798168dccc9e27287c574a9cb5e95b SHA-1: 9548165ba3346c65b59039a929ac7fa75a77132b SHA-256: 5158e837eaea792bfb16d6f6c8a64b28e9c48d61a8c66ef5bc53794ed715b2d2
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document contains numerous external links, many of which point to disposable hosting and are likely part of a link farm. The ML classifier and ClamAV detection strongly indicate malicious intent, specifically phishing or malware distribution. While no scripts were directly extracted, the PDF structure and heuristic firings suggest it's designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 https://laborke.ru/uplcv?utm_term=the+daily+life+of+the+immortal+king+anime+episode+1 PDF link annotation
    • http://aedelsur.com/contenido/files/79367777796.pdfIn PDF document text
    • https://ezsprinting.com/userfiles/file/78771576197.pdfIn PDF document text
    • http://nilesk.com/userfiles/file/47363238930.pdfIn PDF document text
    • http://fatimaartwork.com/userfiles/file/34118059020.pdfIn PDF document text
    • http://www.prunay-en-yvelines.fr/ckfinder/userfiles/files/nubixonazevijekinako.pdfIn PDF document text
    • https://costarica4d.com/contents/files/29696808131.pdfIn PDF document text
    • http://www.louisefarmersmith.com/admin/ckeditor/ckfinder/userfiles/files/53049779833.pdfIn PDF document text
    • https://lanjutpt1.com/contents/files/16096162855.pdfIn PDF document text
    • https://curewelldiabetes.com/userfiles/file/19617423725.pdfIn PDF document text
    • http://carraracucinecomponibilitrapani.it/userfiles/files/11291827623.pdfIn PDF document text
    • https://komunalno.vrgorac.hr/files/8999721145.pdfIn PDF document text
    • https://nitm.ac.in/nitmeghalaya/ckfinder/userfiles/files/78898981154.pdfIn PDF document text
    • http://tgtech-auto.com/userfiles/file/34090390183.pdfIn PDF document text
    • http://lyzebrno.cz/userfiles/file/46036417795.pdfIn PDF document text
    • https://lajovisena.com/gallery/file/gexasenofefazenub.pdfIn PDF document text
    • http://wawa757.com/uploads/files/wuwiru.pdfIn PDF document text
    • http://ttmm.co.jp/ckfinder/userfiles/files/32539459887.pdfIn PDF document text
    • https://sambelteri.com/contents/files/66677634274.pdfIn PDF document text
    • https://wilocom.ro/ckfinder/userfiles/files/44291415174.pdfIn PDF document text
    • https://www.notusweb.com.br/ckeditor/ckfinder/userfiles/files/97535483096.pdfIn PDF document text
    • http://intranet.uts.edu.co/portal/app/ckfinder/userfiles/files/xakaxaloropunix.pdfIn PDF document text
    • https://www.ksmt.edu.np/assets/ckfinder/userfiles/files/logijokenudap.pdfIn PDF document text
    • http://salon-urody-bellis.pl/images/file/tefuji.pdfIn PDF document text
    • https://koltoztetes-szallitas-lomtalanitas.com/ckfinder/userfiles/files/28713211312.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_off0000b0df.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB0DF 17636 bytes
SHA-256: 3284ef1209f3ed85609ff3878986c3842783b4a8f4aad1086d97565cafb7b75c
font_01_sfnt_off0000de85.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE85 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f69c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF69C 11164 bytes
SHA-256: 4ec1cc19f16b153ce7768ba304a89e0d30067c23c36ef8451eb8e8aa060568e5