Malicious PDF — malware analysis report

Static analysis result for SHA-256 85a437191c1d3d52…

MALICIOUS

PDF

71.9 KB Created: 2021-09-25 08:42:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 597231c2787461a07ef7bc3a4aaf73ff SHA-1: f8e5805e83ea3e5269cfc232f80266c2f7a4a0cb SHA-256: 85a437191c1d3d52b44cf3037de6cc101efd728bb19c1faaad39948fdf642c5f
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, containing numerous links pointing to compromised CMS upload directories and disposable hosting. These links likely lead to phishing pages or further malware downloads, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130c79d7ed4c---niredomomisilixofimejafu.pdf In PDF document text
    • http://studiophotosfashion.it/userfiles/files/71718567026.pdfIn PDF document text
    • https://topconta.ro/userfiles/file/57606261425.pdfIn PDF document text
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/b4acdf661a6ad370bc847d15c70ff573/24332384823.pdfIn PDF document text
    • http://kidneytracker.com/ckfinder/userfiles/files/lidekifogokijotisesevuv.pdfIn PDF document text
    • http://dezis.ru/uploads/files/56768832127.pdfIn PDF document text
    • https://www.hed-endo.hr/wp-content/plugins/formcraft/file-upload/server/content/files/16138173315bdd---mepugapog.pdfIn PDF document text
    • http://aiswaryamatrimonials.com/fck_uploads/file/xusakumi.pdfIn PDF document text
    • http://hycxchina.com/filespath/files/20210920182523.pdfIn PDF document text
    • http://ttfi.org/app/webroot/userfiles/file/jirikedobawojerides.pdfIn PDF document text
    • http://kystar.net/filespath/files/20210907124833.pdfIn PDF document text
    • http://xn--80aer5aza.xn--19-kmcm3c.xn--p1ai/ckfinder/userfiles/files/bobawavejoxavirotobexija.pdfIn PDF document text
    • http://yokohama-model.com/userfiles/files/32622660125.pdfIn PDF document text
    • https://allmassage.net/upload/file/20210925093248.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614c154454d1c---jugegowabetitatitodof.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/4eb2c58fa203169c3579b0429bd3cdf7/bazakakijebexi.pdfIn PDF document text
    • http://zhfangyuan.com/uploadfiles/files/xafazutu.pdfIn PDF document text
    • https://beaufortbond.com/wp-content/plugins/super-forms/uploads/php/files/8a400f68f20da9cf7b3ed7105be251c3/22456780046.pdfIn PDF document text
    • http://cbcom.fr/ressource/site-image/files/wokolesofedunanopilakopoj.pdfIn PDF document text
    • http://imhome-listings.com/userfiles/files/dafudomivuvo.pdfIn PDF document text
    • https://brusroom.com/wp-content/plugins/super-forms/uploads/php/files/e466cb300d1769ca38b708f84b112ee2/kukikerekurazakiwibup.pdfIn PDF document text
    • https://doucetplasticsurgery.com/ckfinder/userfiles/files/woronakebewenu.pdfIn PDF document text
    • http://desiaussies.com/ckeditor/uploads/files/32444278207.pdfIn PDF document text
    • https://formapolis.it/wp-content/plugins/super-forms/uploads/php/files/ad7bc3467ac8495a8b8351965f7d8200/53544214149.pdfIn PDF document text
    • https://proetcontra.hu/userfiles/file/2406213215.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=app+edit+video+alight+motionPDF 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_off0000b657.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB657 16912 bytes
SHA-256: 699950047616ae467943c52d437927866f31700b09277163b1832a122c65a0aa
font_01_sfnt_off0000e039.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE039 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f850.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF850 10620 bytes
SHA-256: 35a86dea3f0d9af4559159f40ce296eec787f99bedf11cc618be6481dd13dca2