Malicious PDF — malware analysis report

Static analysis result for SHA-256 c94a50a863222896…

MALICIOUS

PDF

74.8 KB Created: 2021-10-05 00:17:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 640ca718a03a92bc083b592707dd4302 SHA-1: 6ed052dfa6dd11bcda6f0316735fea7d15637d38 SHA-256: c94a50a8632228961f84c8df5109e166c5969962f54abfcdd26b573510c153dd
176 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external websites, some hosted on compromised CMS uploads. The document body is heavily obfuscated, preventing analysis of its direct content, but the presence of numerous URLs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest a malicious intent to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 7

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://ripedesign.com/app/webroot/files/fckeditor/file/suxufajuluvapexifabarus.pdf In PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/16153e3e62abf9---57217883791.pdfIn PDF document text
    • https://hongmao.tw/uploads/files/202109221504244473.pdfIn PDF document text
    • http://skoleniridicu-online.eu/ckfinder/userfiles/files/49133082758.pdfIn PDF document text
    • https://novitas.ro/files/31583827199.pdfIn PDF document text
    • https://divinescience.in/userfiles/file/niliwajowaxesafufuxaliwu.pdfIn PDF document text
    • https://skatrip.com/basefile/skatripcom/files/xekuvumomufigebukuni.pdfIn PDF document text
    • https://bonaparte.cappencms.com/templates/files/42548798178.pdfIn PDF document text
    • http://barrybusiness-crm.com/ressource/devis-photo/files/49731008456.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133365f06ab0---79289214717.pdfIn PDF document text
    • https://xulynuocphangiathinh.vn/images/pic/file/gukeleg.pdfIn PDF document text
    • http://zatoodesign.com/userfiles/files/furilowevupepizifadaguzej.pdfIn PDF document text
    • http://stroyvodservice.ru/upload/File/kikakizaxife.pdfIn PDF document text
    • http://onlinemidias.com/ckfinder/userfiles/files/wuwujeviremifura.pdfIn PDF document text
    • https://sunrise-photon.com/upfiles/editor/files/39844348980.pdfIn PDF document text
    • http://leylasuren.com/images/userfiles/imagefile/29763244531.pdfIn PDF document text
    • https://processwork.archerhuang.com/ConImg/files/81617079722.pdfIn PDF document text
    • http://zoltysnieg.pl/pliki_wyswig/files/sowixidalepafumil.pdfIn PDF document text
    • http://cokhihoaiduc.com/uploads/files/tuvirekawikajamadavugigi.pdfIn PDF document text
    • http://tw-jia.com/uploads/files/202109082214209000.pdfIn PDF document text
    • https://baatco.com/ckfinder/userfiles/files/46849598790.pdfIn PDF document text
    • http://studiotecnicolari.it/userfiles/files/nadonajemulakuvojo.pdfIn PDF document text
    • http://www.thaiboat.net/image/upload/File/zuforiwuvew.pdfIn PDF document text
    • http://stopasbestos.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613c845e8997f---mokuzunuzobob.pdfIn PDF document text
    • http://psychanalyste-gard.fr/ckfinder/userfiles/files/938103517.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=loss+carry+backPDF 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_off0000c2e3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2E3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000dafa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAFA 10052 bytes
SHA-256: 7c68abc5969925f0101a91c3c2b75422d74ab766867ac5bf85b4bf0a4568f95d
font_02_sfnt_off0000f188.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF188 17352 bytes
SHA-256: 835fb1fae51f12e651bd97aa3a7d07444fffc63ac07aab4bf2f39c05c76facfc