Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8741ce6d9282ebf…

MALICIOUS

PDF

86.5 KB Created: 2021-09-06 00:23:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 1e01779c272f5646ff26c64d2e66dba8 SHA-1: 801d509fa343159d499e7af99b1c58dca2dc3d41 SHA-256: c8741ce6d9282ebf03ecacaa8ce3e9df631f9abd5369775a89f4455eae30b47e
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, providing no direct user-facing content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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 http://mfahk.com/upload/files/nekurinoravojumok.pdf In PDF document text
    • http://granitemountainranch.net/userimages/muxanimidixawazexitar.pdfIn PDF document text
    • https://cafepiolho.com/uploads/assets/47128210588.pdfIn PDF document text
    • https://motacademy.it/file/piralazuxelu.pdfIn PDF document text
    • https://tasleemdubai.com/userfiles/files/fusejopemoxa.pdfIn PDF document text
    • https://shopexpert.com/app/webroot/files/userfiles/files/71698337660.pdfIn PDF document text
    • https://apz-arte.com/ckfinder/userfiles/files/47009059016.pdfIn PDF document text
    • http://niestachow.pl/data/aktualnosci_imgs/file/35570434373.pdfIn PDF document text
    • https://btegypt.com/file/49455839712.pdfIn PDF document text
    • http://www.virtualaid.eu/wp-content/plugins/formcraft/file-upload/server/content/files/1606cb52c734a6---xupekedulasidapebala.pdfIn PDF document text
    • https://radmangroup-ye.com/rgfiles/file/misekeboloxewapawowo.pdfIn PDF document text
    • https://bagstyle.uz/images/file/91454000193.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/cfefcd5ba5501bfccf47e596f3a303fe/42024014091.pdfIn PDF document text
    • http://eko-inwest.eu/upload/file/valimizarujip.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/guruvak.pdfIn PDF document text
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160945b81e6f57---kazonafaxunogavum.pdfIn PDF document text
    • https://www.syah.org/wp-content/plugins/super-forms/uploads/php/files/6b5ea18c5001be9c558a00eb248750cd/dirojimufuvogibi.pdfIn PDF document text
    • https://fiambreszav.com/wp-content/plugins/super-forms/uploads/php/files/c9b52e3b141a27a5dc34a2ad25d98f72/67091081879.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/9383632880.pdfIn PDF document text
    • http://geoodwierty.pl/files/file/piworip.pdfIn PDF document text
    • http://erpos.sk/data/files/91640138523.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/t9mltu5fdkeumaubcf4v4dk547/zefiresesifag.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a2e505cbfd4---35900318293.pdfIn PDF document text
    • https://mercedesmazo.es/wp-content/plugins/formcraft/file-upload/server/content/files/160ab24f7d7f98---91477964432.pdfIn PDF document text
    • https://kochitaxirental.com/ckfinder/userfiles/files/susafetibegeko.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=molecular+orbital+theory+for+heteronuclear+diatomic+molecules+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_off0000e7cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7CF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ffe1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFE1 18896 bytes
SHA-256: 3b29be4dbf474ee1f7d178511d55f5f12b489187d936bce7f87fe86ba08ff7ad
font_02_sfnt_off000131f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x131F0 11232 bytes
SHA-256: ba433de527e83356d21e7c5ffde89a078499f1f235dfeb7bca2dbafb3da3812a