Malicious PDF — malware analysis report

Static analysis result for SHA-256 9964834ef06b657b…

MALICIOUS

PDF

90.3 KB Created: 2021-10-18 13:11:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 9499f38c20b7b3474ee52b6f233eb0ac SHA-1: fcd20ba77af03eb933a846d24ced9e81bf84447b SHA-256: 9964834ef06b657b610fad81cb845c7500a3bb70683846a761b1c86896782c63
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was detected as a malicious PDF by ClamAV and an ML classifier. It contains numerous embedded URLs, many of which point to other PDF files hosted on various domains, indicating a link farm or distribution network. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggests this purpose. While no scripts were extracted, the structure and URL patterns are indicative of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://0225674989.kad.tw/kads/ckfinder/userfiles/files/27886566476.pdf In PDF document text
    • https://cansandientu.net/Images_upload/files/kenawu.pdfIn PDF document text
    • https://hijaustabilo.com/contents/files/53985103099.pdfIn PDF document text
    • https://takarasushimn.com/userfiles/files/wanovedekubogosiwalo.pdfIn PDF document text
    • http://www.findvoters.com/userfiles/file/78964940685.pdfIn PDF document text
    • http://dmkert.hu/files/file/newiwusofinu.pdfIn PDF document text
    • http://www.anclupnapoli.it/userfiles/file/52380700934.pdfIn PDF document text
    • https://afayl.com/userfiles/file/73743783920.pdfIn PDF document text
    • https://adeptos.clevercloud.pt/images/items/files/7899336932.pdfIn PDF document text
    • http://oticonshop.net/ckfinder/userfiles/files/nidugutavijonakomudakul.pdfIn PDF document text
    • http://asesoriagarpe.com/wp-content/plugins/formcraft/file-upload/server/content/files/161681dae5e2b2---geniwet.pdfIn PDF document text
    • https://masukpt2.com/contents/files/juwajabeduduzusiwub.pdfIn PDF document text
    • http://topspeed4wd.com/ckfinder/userfiles/files/luzupozuludavus.pdfIn PDF document text
    • https://traveletrust.com/basefile/traveletrustcom/files/84276149185.pdfIn PDF document text
    • https://solener.info/ckfinder/userfiles/files/5911761520.pdfIn PDF document text
    • http://fslawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/25882647623.pdfIn PDF document text
    • http://slkuang.com/v15/Upload/file/2021916045325291.pdfIn PDF document text
    • https://whereestar.com/marinarubicon/admin/file/nofekamujemaluma.pdfIn PDF document text
    • http://driscollandgibson.com/images/edit_images/file/vivolubokanafo.pdfIn PDF document text
    • https://collinite.pl/userfiles/file/gisemujiwugelan.pdfIn PDF document text
    • https://gamletaarnhuset.no/wp-content/plugins/formcraft/file-upload/server/content/files/1613554000ed06---buronif.pdfIn PDF document text
    • http://workontext.ru/media/file/nonor.pdfIn PDF document text
    • http://abworder.com/uploads/files/5266502192.pdfIn PDF document text
    • http://gndpta.eu/news_objects/files/89649670751.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/23D8k0Ec_6w/uplcv?utm_term=length+of+the+curve+calculatorPDF 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_off0000f4eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4EB 10480 bytes
SHA-256: 015223f3a81eadb5a9faa4d3abde2e154d3a381c8657f22ef9f4a82d0bc398fc
font_01_sfnt_off00010cb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CB3 20984 bytes
SHA-256: 4914ee00439f53ce3755e36fa9f464ef7f2d63deb54c8461c802fa9b31fac5bf
font_02_sfnt_off0001435c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1435C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1