Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8b772eb00f17bc1…

MALICIOUS

PDF

73.6 KB Created: 2021-09-07 16:55:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 6795bbfeb62a94edf423073095510ea9 SHA-1: b11ed32d46d72cc69d3505d1502e811b9bf587df SHA-256: d8b772eb00f17bc12d2e8c0b672f90221dfe7bd99aa2ec7433db234aeff9de50
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised or disposable domains, indicating a link farm designed to redirect users. Heuristics suggest this is a phishing or malware distribution attempt, with ClamAV specifically identifying it as Pdf.Phishing.Trojan. The ML classifier also strongly flagged the PDF as malicious. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content to analyze.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://cructi.ru/uplcv?utm_term=estiba+de+carga+en+camiones+pdf PDF link annotation
    • http://gonvvama.net/filespath/files/20210902014559.pdfIn PDF document text
    • http://dambi.pl/userfiles/file/repujol.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160886aa669569---54087649463.pdfIn PDF document text
    • https://thuaphatlaihanoi.net/uploads/files/fawawajabetonopoke.pdfIn PDF document text
    • http://blpest.com/UserFiles/file/dirimuf.pdfIn PDF document text
    • https://digireg.si/upload/3623990866.pdfIn PDF document text
    • http://cavusofis.com/images_upload/files/17784337598.pdfIn PDF document text
    • https://www.qlsny.com/wp-content/plugins/super-forms/uploads/php/files/bcff0cb5133516f11393d5b4b721dbec/rotofopowevikozepaxofa.pdfIn PDF document text
    • http://cwesp.biz/upload/file/85320334762.pdfIn PDF document text
    • http://nmways.com/uploads/fckupload/file/fepidos.pdfIn PDF document text
    • http://tajeer.co/userfiles/file/boxibajalapolodubujab.pdfIn PDF document text
    • http://www.akutrans.com/wp-content/plugins/formcraft/file-upload/server/content/files/160923542d1992---kobemifogazavedo.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/mf2knu6hmipuff3apnh72h8de8/lijaxusifixiduvog.pdfIn PDF document text
    • http://ipllaser.in/uploads/33457400722.pdfIn PDF document text
    • https://newoptic.mn/uploads/files/pedujujubaribe.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac80fa69310---98790288602.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/8211jq98grqhbg66elvsgheb3v/9687177426.pdfIn PDF document text
    • https://sabunwangi.com/contents//files/runanusanapebotiwo.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f3859a4b79---fazilolasalunusuvuroxaze.pdfIn PDF document text
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/ab68ab5bbc6c9a65c53b60b0f760ab36/fopebukigadefalu.pdfIn PDF document text
    • http://fazendasaojudastadeu.net/fotosempresa/files/putigakofa.pdfIn PDF document text
    • https://www.skyline-recruiting.com/wp-content/plugins/super-forms/uploads/php/files/8cc2633b35f97246544665308edef0c3/xabobutejafetawitiputexil.pdfIn PDF document text
    • https://gccpay.net/wp-content/plugins/super-forms/uploads/php/files/b7f6e72e24a4e2a376b19c440f00551e/99104129079.pdfIn PDF document text
    • http://ohsongpharm.com/ckfinder/userfiles/files/62650959609.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/077202105a327623cb86e5a3521710e1/dexokovipevigagugep.pdfIn PDF document text
    • http://kurier48.pl/files/userfiles/file/87069154145.pdfIn 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_off0000bb48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB48 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d35f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD35F 11040 bytes
SHA-256: 4f23c1ca5f859b4ef48e61fd9308e13611eee549fd8e2f4a748c96e0f6600927
font_02_sfnt_off0000ec9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC9C 17008 bytes
SHA-256: 3b713494eabea9f7e098b737773107e0b5fe3a8a196a98f31919026a4ef78048