Malicious PDF — malware analysis report

Static analysis result for SHA-256 9c498aed5d28630e…

MALICIOUS

PDF

80.9 KB Created: 2021-09-08 13:42:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: a82989d775a414300d73381e095cd893 SHA-1: 8b8df7d492052a166e7010cf321196abd1105228 SHA-256: 9c498aed5d28630e8343ee2f39155719ebd884fabda37f4500862bfa037a3510
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external URIs, with one heuristic specifically identifying it as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent. While no scripts were directly extracted, the PDF structure and the presence of many unknown reputation URLs suggest it is used to redirect users to potentially malicious sites, likely as part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 http://palestraarkadia.it/userfiles/files/5208959664.pdf In PDF document text
    • https://almuhja.net/ckfinder/userfiles/files/luxizikezasumomonojopixe.pdfIn PDF document text
    • https://liftsystems.ro/LiftFiles/file/61608831325.pdfIn PDF document text
    • https://onlineadda.net/ckfinder/userfiles/files/31978621874.pdfIn PDF document text
    • https://stratasphere.online/userfiles/file/xubijexiwev.pdfIn PDF document text
    • http://donateagift.eu/userfiles/file/97743544108.pdfIn PDF document text
    • http://premiercontainerlines.com/media/ftp/file/nozajawozorokazalojilumam.pdfIn PDF document text
    • https://fnb-concepts.com/images/uploads/files/xiwapasutoxa.pdfIn PDF document text
    • http://tabouligrill.com/ckfinder/userfiles/files/fuwosomerazevadijeled.pdfIn PDF document text
    • http://americasbestwingsbeltsville.com/uploads/files/48692688562.pdfIn PDF document text
    • http://2018.letnifestiwal.pl/ckfinder/userfiles/files/zibaviribuvagewat.pdfIn PDF document text
    • http://www.bargiel.com.pl/ckfinder/userfiles/files/98957230244.pdfIn PDF document text
    • http://daming-school.com/userfiles/file/76700117078.pdfIn PDF document text
    • http://www.training4thefuture.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1612f154203ae6---besafebezujujefidituriro.pdfIn PDF document text
    • https://www.weldcor.ca/public/ckfinder/userfiles/files/53803807848.pdfIn PDF document text
    • http://cicm2015.mist.ac.bd/app/webroot/ckfinder/userfiles/files/5293931249.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136e3ab338ac---46741165065.pdfIn PDF document text
    • https://conexus-study-abroad-travel.com/ckfinder/userfiles/file/gusamegixonerujavuv.pdfIn PDF document text
    • http://dnepropress.net/files/file/punedukusuzirunuxuzu.pdfIn PDF document text
    • http://mackielaw.net/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/jokikalamemuxiresanop.pdfIn PDF document text
    • http://sungwoneng.com/upfile_editor/2021/files/23545800366.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=6th+grade+math+sol+review+worksheetsPDF 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_off0000d6fe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6FE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ef10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEF10 17836 bytes
SHA-256: a3cf9b1a97163df122084c6e6b7f46ab7b67fb22ce5cb1d9bf122ad6bf8a34f2
font_02_sfnt_off00011d1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D1C 10908 bytes
SHA-256: 1c4f3a13acc99c539988fcc80b725ef6e342cf8f6625e4fc0b63f38098529c21