Malicious PDF — malware analysis report

Static analysis result for SHA-256 21f0a0baa38933e5…

MALICIOUS

PDF

86.5 KB Created: 2021-09-07 21:46:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 74b01ec5281e1bff04295136d7a1c9f6 SHA-1: 6da73142064cbf5573139e2211e9379e51a33306 SHA-256: 21f0a0baa38933e599021cbc61afa71d1db6b654a22d3534500d04f0946d6f51
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to compromised websites and disposable domains, suggesting a link farm used for SEO manipulation or to host malicious content. The document body is heavily obfuscated and unreadable, preventing a more detailed analysis of its specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9848

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 http://arohitourandtravels.com/userfiles/file/pomowediteserawisil.pdf In PDF document text
    • http://www.luminicaambiental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b05a9d283bf---8103592554.pdfIn PDF document text
    • http://ukrainski-rosyjski.pl/userfiles/file/12994844457.pdfIn PDF document text
    • http://dgjst.com/upfile/file/mizamakonanepexen.pdfIn PDF document text
    • http://elliptical-trainers.ru/ckfinder/userfiles/files/liloderar.pdfIn PDF document text
    • http://fiumaradelsossio.it/userfiles/files/wonuviwiperuse.pdfIn PDF document text
    • http://school19-zav.ru/userfiles/file/48698087740.pdfIn PDF document text
    • https://creteservices.com/FCKeditor/userimages/file/63249307261.pdfIn PDF document text
    • https://kfz-gutachter-oliver-schiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ca410e64185---13401404324.pdfIn PDF document text
    • http://norilskgu.ru/userfiles/file/15523636801.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/3be236f0366f284d6765f2ee6555ed8d/68507761801.pdfIn PDF document text
    • http://getawaynewzealand.co.nz/wp-content/plugins/formcraft/file-upload/server/content/files/160a02eddcfd5f---1334434090.pdfIn PDF document text
    • http://becucci.it/userfiles/files/82598686271.pdfIn PDF document text
    • http://www.leasebridge.com/CKUPimg/files/97270971436.pdfIn PDF document text
    • http://yongqingtech.com/d/files/67124189109.pdfIn PDF document text
    • http://alemotta.com/resources/original/file/vefeno.pdfIn PDF document text
    • http://odnoklassniki-files.ru/images/uploads/files/rojotojisolegom.pdfIn PDF document text
    • https://interesttour.com/wp-content/plugins/super-forms/uploads/php/files/c37499ce9fdf1c4ced4f4bc9d0b5bcd0/muradepifepaxatuxar.pdfIn PDF document text
    • http://www.sunargrup.com.tr/wp-content/plugins/super-forms/uploads/php/files/klcr5bt4jsou9k6bfd12onv2t7/72447741397.pdfIn PDF document text
    • http://hoangle.vn/uploads/userfiles/file/4187214195.pdfIn PDF document text
    • https://arerp.kr/data/file///2009228682.pdfIn PDF document text
    • http://gennarimaq.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b2c23b54816---sidezoxitusil.pdfIn PDF document text
    • http://asorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/bowipevur.pdfIn PDF document text
    • http://alexlunacoach.com/img/editor/file/34126677522.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1611e355dc79df---39347578923.pdfIn PDF document text
    • http://patanamachine.com/imgUpload/files/maporugiwegefuwiw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=coxartrosis+elsevier+pdfPDF link annotation
    • http://hdl.handle.net/2445/99241In PDF document text
    • 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_off0000eb67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB67 18776 bytes
SHA-256: 142ff6145944c68229b91baf21b861b46adaf34637c539c4f962fe0d7de27944
font_01_sfnt_off00011c25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C25 10588 bytes
SHA-256: e2ab9f1ff56f598e4d51a22d2826c69027aee1d423c3cae2b5771428b3dbead7
font_02_sfnt_off00013488.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13488 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1