Malicious PDF — malware analysis report

Static analysis result for SHA-256 91a4f9515163dd78…

MALICIOUS

PDF

84.0 KB Created: 2021-08-22 03:09:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 478012a9284db8060a624fdbfc2214e1 SHA-1: 4cb32c06f8b5c0b6b76d9a22e31f0e2c6996f259 SHA-256: 91a4f9515163dd783ad726eadef48849ba18858028c4de667984e7df8e49cdb5
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, embedding numerous URLs that point to compromised CMS uploads and disposable hosting, likely to redirect users to phishing or malware sites. The presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest this document is part of a campaign to distribute malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://www.sacda.org/wp-content/plugins/super-forms/uploads/php/files/8vicbf62fpici4oudrfj0p6v03/vitonaroxuvefan.pdf In PDF document text
    • https://mahae.hu/files/files/56151212690.pdfIn PDF document text
    • http://shshalloffame.com/clients/9/93/936f23dc4abb03f6d4a1aae2c8a32781/File/7702683868.pdfIn PDF document text
    • http://araonline.hu/uploads/file/lotowewopaferiperuvebenuk.pdfIn PDF document text
    • https://www.kalirich.com/wp-content/plugins/super-forms/uploads/php/files/ojmtrtqqcmfrc6j6f9u7s2iff2/78531643592.pdfIn PDF document text
    • http://seoulsquare.com/userfiles/file/14145910493.pdfIn PDF document text
    • http://dbjhockeytournament.com/clients/f/f9/f9ff496842c877cbb4522510b668f2a2/File/xebezaxajenogeg.pdfIn PDF document text
    • http://www.britocunhaadvocacia.com.br/home/wp-content/plugins/formcraft/file-upload/server/content/files/16081eec88633b---gufiso.pdfIn PDF document text
    • http://minuspk.ru/minuspk.ru/userfiles/file/46475715218.pdfIn PDF document text
    • http://www.kevinbrooks.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606f5292a6663---5941206742.pdfIn PDF document text
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16074c92627b7e---44039143148.pdfIn PDF document text
    • http://geose.ru/userfiles/file/seles.pdfIn PDF document text
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16073299e3270a---3993405346.pdfIn PDF document text
    • https://www.femregenx.co.za/wp-content/plugins/super-forms/uploads/php/files/3e7i6p63rbuq89da7ir7rojn3c/saxeno.pdfIn PDF document text
    • http://eventologia.com/userfiles/files/roropaxixozani.pdfIn PDF document text
    • http://math-talk.kr/wp-content/plugins/super-forms/uploads/php/files/p2f7kqg34m9fcs0bogvmbip5ki/77420230849.pdfIn PDF document text
    • http://ozari-ua.com/files/file/dalez.pdfIn PDF document text
    • http://kotolantopeni.cz/file/dozevipupedugam.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/99881933393.pdfIn PDF document text
    • https://alarrabnews.com/images/content/content/file/fixibaligugamujisuv.pdfIn PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1606e8f9a259da---lomutipalil.pdfIn PDF document text
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/553b8bf21d57c25d7b434e8c8939b8f7/43934457766.pdfIn PDF document text
    • http://yetisirkaucuk.com/firma/files/jowidadivaf.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/Om9ozkHLxGw/uplcv?utm_term=area+of+squares+rectangles+and+triangles+worksheet+pdfPDF 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_off0000e1de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE1DE 17268 bytes
SHA-256: 7780d8659c1aefb14a59a69fce7730b677d4f52ab7bd57df4704762c6c1d859b
font_01_sfnt_off00010f3c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F3C 11304 bytes
SHA-256: f3cb248f3c31ab96051e612131fba44185729ae424bca2eb28b5d111184704c6
font_02_sfnt_off0001294d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1294D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1