Malicious PDF — malware analysis report

Static analysis result for SHA-256 8ccd85c5e375a283…

MALICIOUS

PDF

83.1 KB Created: 2021-10-02 11:07:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 6bd6145913c22f539979d2b397e9ebc5 SHA-1: 04b410df03274cc7c2fd8be00060d85689f2f86d SHA-256: 8ccd85c5e375a283fe91a0180bef1c53591daa13fd8acb9b5a5df67a2c045e54
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as a phishing trojan and by an ML classifier as malicious. It contains numerous embedded URLs, many of which point to potentially malicious PDF files hosted on various domains, suggesting a link farm designed to redirect users to malware. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure malicious links. No scripts were extracted, but the overall structure and URL distribution point towards a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9931

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://www.benkorner.nl/admin/library/ckfinder/userfiles/files/92899609711.pdf In PDF document text
    • http://angerdress.store/ckfinder/userfiles/files/66245479713.pdfIn PDF document text
    • https://sudhirsachdevaclasses.com/ci/userfiles/files/42152522050.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614ddada780a1---fedepemosa.pdfIn PDF document text
    • http://jfac.kr/ckfinder/userfiles/files/luselonisunaje.pdfIn PDF document text
    • http://mail-business.ru/uploads/file/40844374657.pdfIn PDF document text
    • https://zilalcooling.com/other_files/File/8470824434.pdfIn PDF document text
    • http://meskerjager.nl/media/files/2636022475.pdfIn PDF document text
    • https://kimansion.com/uploads/file/46284260650.pdfIn PDF document text
    • https://brazilairporttransfers.com/ckfinder/userfiles/files/29839063927.pdfIn PDF document text
    • https://nguyenthelong.net/userfiles/files/kotupomofiluromavisisebe.pdfIn PDF document text
    • https://fancybox.pamlskovnik.cz/ckfinder/userfiles/files/48544176124.pdfIn PDF document text
    • https://pirkitpadangas.lt/ckfinder/userfiles/files/gevoxujitukerap.pdfIn PDF document text
    • http://saatgaamkansarasamaj.com/admin/uploads/files/58421404654.pdfIn PDF document text
    • https://www.nstoplana.rs/ckfinder/userfiles/files/zasow.pdfIn PDF document text
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/rd0fvtvc89d9jknaocptkj0m39/86519023062.pdfIn PDF document text
    • http://vikohasanfiber.com/upload/files/zajusevowen.pdfIn PDF document text
    • https://ozmutludokum.com/userfiles/file/fuvijojafegenapigub.pdfIn PDF document text
    • http://islandpointfl.com/userimages/rabegebidasixige.pdfIn PDF document text
    • http://formpart.com/upload/ckfinder/files/12184264653.pdfIn PDF document text
    • https://ecpa.fr/uploaded/file/55298469934.pdfIn PDF document text
    • http://architettoannalisatinelli.it/userfiles/files/zavavuwavok.pdfIn PDF document text
    • https://photofetimages.com/72008236170.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=adobe+after+effects+portable+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_off0000be52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE52 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d663.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD663 16188 bytes
SHA-256: 800554d3d6320da9c8ab21a3ad3d270f40e7a92360d7538c059d647d952d1d34
font_02_sfnt_off0000ec15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC15 22200 bytes
SHA-256: 5687d17bfae3b207de060c467c2132536c551e2e89a53d28c7c72d14fbb76a47
font_03_sfnt_off00012593.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12593 10728 bytes
SHA-256: 2e6370cd33cf46d5cf7f363bd8404a415fad92035d0b9b625bdc8897dcbff327