Malicious PDF — malware analysis report

Static analysis result for SHA-256 73b5351809aaa3ab…

MALICIOUS

PDF

77.5 KB Created: 2021-09-24 06:46:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 6517e38e9e1d9e7d5a2655d5f89d6dbd SHA-1: 8ef7938ec66241b541ca58f028b4327aa5e08bf1 SHA-256: 73b5351809aaa3abca39bc6b681a2434961439f9f197f117eca027c0d23a6dd3
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting. While no scripts were explicitly extracted, the PDF structure and the presence of many external links suggest it's designed to redirect users to potentially harmful websites, likely as part of a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://brlairport.com/images/file/butizanawipojovabefukedo.pdf In PDF document text
    • https://petandpuppies.com/userfiles/file/bigulazazowumedixebobito.pdfIn PDF document text
    • http://bettaletroom.com/file_media/file_image/file/73005336125.pdfIn PDF document text
    • http://vswet.ru/f/mosilukupurabejiran.pdfIn PDF document text
    • http://musthighschool.mn/ckfinder/userfiles/files/marekidupej.pdfIn PDF document text
    • http://latiendasegura.com/contable_prueba/userfiles/file/gogikewafopofupabekiti.pdfIn PDF document text
    • http://niktid.ru/userfiles/file/zemetalaleka.pdfIn PDF document text
    • http://janjoling.com/public/ckfinder/userfiles/files/lolufowizu.pdfIn PDF document text
    • https://icicle-mountaineering.ltd.uk/ckfinder/userfiles/files/vozitugumada.pdfIn PDF document text
    • https://textosolutionslinguistiques.com/upload/editor/file/63302376144.pdfIn PDF document text
    • https://takipcisec.com/calisma2/files/uploads/kixekebokog.pdfIn PDF document text
    • http://pattarasawat.com/ckfinder/userfiles/files/tizewamutofodaburu.pdfIn PDF document text
    • https://slide-bearing.com/d/files/tabuziwemekupigi.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/jibotilipijivafuxifet.pdfIn PDF document text
    • http://ombs.ru/uploads/files/rarabujareruxa.pdfIn PDF document text
    • http://cnc-soustruzeni.cz/files/file/75302126401.pdfIn PDF document text
    • https://polandpools.com/contents/files/fadubatipipomef.pdfIn PDF document text
    • https://thefencedocumentary.ca/adminfiles/file/tefivupidukejipep.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b8ff9b508b---31468858783.pdfIn PDF document text
    • http://clarklawtexas.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/zulupawu.pdfIn PDF document text
    • http://shopphutungmayphat.com/upload/img/files/ruduropinilaripibimale.pdfIn PDF document text
    • http://www.prodomasa.com/ckfinder/userfiles/files/betuvo.pdfIn PDF document text
    • http://spostojow.pl/userfiles/file/zudinalokonewojubinumepos.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=bloc+de+notas+para+android+en+espa%C3%B1olPDF 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_off0000c7f7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC7F7 10768 bytes
SHA-256: 57640bd1b890e4834539bbcef803f0dc7f5fa702006aa81ea4b8457a3842d0e8
font_01_sfnt_off0000e099.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE099 17900 bytes
SHA-256: a6ffeeb1300feac4b9c4d954cff2e2c883a736539438c662aed32901c8b11355
font_02_sfnt_off00010e04.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E04 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1