Malicious PDF — malware analysis report

Static analysis result for SHA-256 9d410117e6f5887d…

MALICIOUS

PDF

76.1 KB Created: 2021-09-13 23:10:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: a6c741b1c88c26150042bc79c72c5cfb SHA-1: 5a879c178a33677d379d310d5dd0ed7d472a0804 SHA-256: 9d410117e6f5887d647adaf3b004bec83baa130acdd67fb8d705190e8aa1bf50
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of external links, many of which point to compromised CMS upload directories. The ML classifier and ClamAV detection strongly indicate maliciousness. While no scripts were explicitly extracted, the PDF structure and link farm behavior suggest it's designed to lead users to malicious content or phishing sites, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://www.db-ynox.fr/ckfinder/userfiles/files/69887526.pdf In PDF document text
    • https://unovosti.tv/ckfinder/userfiles/files/54995988649.pdfIn PDF document text
    • http://3bbb.fr/ckeditor/upload/files/faromofar.pdfIn PDF document text
    • http://isdoor.ru/uploads/files/tukegujaxapupoxili.pdfIn PDF document text
    • https://hygradeinsulators.com/images/uploads/file/36736498868.pdfIn PDF document text
    • https://stpetejazz.com/wp-content/plugins/super-forms/uploads/php/files/37t1t326uq8va5b2b432ik2s3r/rezuxavanubumubobimep.pdfIn PDF document text
    • https://ctners.com/ckfinder/userfiles/files/lazod.pdfIn PDF document text
    • http://asja.ua/userfiles/file/refevug.pdfIn PDF document text
    • http://federicozucchettiarchitetto.eu/userfiles/files/10531675098.pdfIn PDF document text
    • https://www.wikiwebagency.it/wp-content/plugins/super-forms/uploads/php/files/061be6b7e8b4e813286f860c0c7076af/tifodokebasatamoviseg.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613672fb93246---xadofakatuvafowopubu.pdfIn PDF document text
    • http://cn-polylysine.com/d/files/tukukinaranovozalos.pdfIn PDF document text
    • https://aksusu.com/upload/files/25396746579.pdfIn PDF document text
    • http://dejede.com/userfiles/file/43713548092.pdfIn PDF document text
    • https://luatsuavina.com/userfiles/file/pokedowukufoxajokupovo.pdfIn PDF document text
    • http://www.mbk-montage.nl/ckfinder/userfiles/files/26987440859.pdfIn PDF document text
    • http://messtores.ca/fck_user_files/file/20179438173.pdfIn PDF document text
    • http://kahasat.cz/data/file/16779783219.pdfIn PDF document text
    • http://satcomlink.com/userData/board/file/86718533331.pdfIn PDF document text
    • http://llux.vn/uploads/files/dedeku.pdfIn PDF document text
    • http://chengzechem.com/upload/files/84731516170.pdfIn PDF document text
    • http://behtarinekhodetbash.com/files/files/jivojigejegigubu.pdfIn PDF document text
    • https://12shio1.com/contents/files/ruxivuxeku.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=words+with+p+and+z+in+themPDF 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_off0000c716.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC716 10748 bytes
SHA-256: 614e575f341c4964417946559c2aac5a865e8076d5b28bba567621a7d1f65b88
font_01_sfnt_off0000dfb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFB1 16744 bytes
SHA-256: d77f4e3ea59433dc1ae98a6e825f8b5cb92ea4d7353d2d24a38e90326acb3a63
font_02_sfnt_off00010aeb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AEB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1