Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b3271c1eef0c92b…

MALICIOUS

PDF

84.6 KB Created: 2021-09-02 07:07:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 05a97b577d82e525932160d4309356c2 SHA-1: 9de3195746189e7c44a6baf51cad54ac1ef3edbd SHA-256: 8b3271c1eef0c92b2c397c4f63968829527be054403198b6de614543e3ca6245
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The heuristics reveal it functions as a link farm, directing users to compromised WordPress uploads and other domains, with one URL specifically mentioning 'flash+animate+download' as a lure. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://mdsalon.ru/img/lib/file/69620755290.pdf In PDF document text
    • https://miaousland.fr/ckfinder/userfiles/files/zixibefekagikajavuvetemon.pdfIn PDF document text
    • http://kolaykanal.com/userfiles/files/bilujetefazuda.pdfIn PDF document text
    • http://briarcliff68.com/clients/71184/File/delan.pdfIn PDF document text
    • https://ptogel2.com/contents//files/dadomawajanusi.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16089a56a4916e---82912179282.pdfIn PDF document text
    • https://independentmusicleague.com/wp-content/plugins/super-forms/uploads/php/files/65f3eb3b3e66dc3e9d27285e24aaa2e6/45677365482.pdfIn PDF document text
    • https://www.tristar-technology.com/ckfinder/userfiles/files/vokexur.pdfIn PDF document text
    • https://proektasis.gr/admin/spaw2/uploads/files/30911200588.pdfIn PDF document text
    • https://flyfinz.com/userfiles/files/5430318938.pdfIn PDF document text
    • http://galerie45.com/userfiles/file/25560154926.pdfIn PDF document text
    • https://m-isc.com/userfiles/file/barelugokizosowifan.pdfIn PDF document text
    • http://tarnava.eu/user_images/file/51593106924.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/16100a025806a4---99393268132.pdfIn PDF document text
    • http://manufim.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/160c856257b2e3---kojow.pdfIn PDF document text
    • http://faisaltowel.com/survey/userfiles/files/deremigekerusurazipinizej.pdfIn PDF document text
    • http://sugarfree-gelato.com/upload/file/28577952484.pdfIn PDF document text
    • https://qian-ho.com/upfiles/editor/files/ziref.pdfIn PDF document text
    • https://laptoptranganh.com/data/dulieu/files/tisej.pdfIn PDF document text
    • http://dtcguild.org/clients/80367/File/pugetomovorumufumukiboge.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/16072107b2498f---bitokex.pdfIn PDF document text
    • https://etre-cheval.fr/Applications/MAMP/htdocs/etre%20cheval/news_pix/file/52174332946.pdfIn PDF document text
    • https://soalmatematik.com/userfiles/file/zovaxerafefiwegupozadaror.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076bcd49d141---3160850075.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=flash+animate+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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e29d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE29D 10476 bytes
SHA-256: 6f5f6736abb166ac3228e48738c09daf7b33b2025cb37c55861cb4ff1852bb67
font_01_sfnt_off0000fa3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA3D 19340 bytes
SHA-256: ad79eb98b0fe0c2fb08e80d5ab737bc63825f5222d5307735f56145c8ce21999
font_02_sfnt_off00012d09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D09 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1