Malicious PDF — malware analysis report

Static analysis result for SHA-256 8e81e522268db05c…

MALICIOUS

PDF

81.9 KB Created: 2021-09-07 04:02:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 4b1aeb307e54659af9c1ecef2ea3ac0e SHA-1: af55f163764631d597eb87c078cdae2486173aa1 SHA-256: 8e81e522268db05c1e19b846570ebe41aec76b7a869ae06177016b5b2532946c
156 Risk Score

Malware Insights

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

This PDF was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, directing users to multiple compromised WordPress sites. These sites, in turn, host further PDF files, suggesting a multi-stage redirection or download process designed to obscure the ultimate payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a486709b124---nivikuk.pdf In PDF document text
    • http://chalappuram.com/userfiles/file/simog.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16114248185fa0---39923409400.pdfIn PDF document text
    • http://dragonera.cn/admin/userfiles/file/46285678253.pdfIn PDF document text
    • http://360global.ca/userfiles/file/gonabigalovujativevesega.pdfIn PDF document text
    • http://robalton.es/Albums/images/file///67052380897.pdfIn PDF document text
    • http://gd-weimi.com/upfolder/e/files/20210731052242.pdfIn PDF document text
    • http://nepodoshlo.kz/ckfinder/userfiles/files/kuvolonibe.pdfIn PDF document text
    • http://meijialx.com/ckfinder/userfiles/files/tegipabuwibitulesegal.pdfIn PDF document text
    • http://stroynerud-sm.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607b4283902c5---gidutibavadazapo.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/160ac6fc10214d---dogiraxolorewurudawapereg.pdfIn PDF document text
    • http://ziva-muzika.cz/files/file/meferupukuxekijosuje.pdfIn PDF document text
    • http://roughriders66.com/clients/f/fa/fa96273273f04fd2a06feef12b1e4d70/File/97450183659.pdfIn PDF document text
    • https://www.oasipizza.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c01741c714b---zakajozakewazek.pdfIn PDF document text
    • http://huijingweb.com/upload_fck/file/2021-7-7/20210707074252272818.pdfIn PDF document text
    • https://fortlauderdale-carservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16100474d0451d---powaku.pdfIn PDF document text
    • https://afanasyev-design.ru/wp-content/plugins/super-forms/uploads/php/files/79445bef8c491a48213af853f8f62a88/58134794262.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606edee28a4c5---pugeduvusu.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/u1fbj1h82pc1ta84nuvumsbuue/denugovasafi.pdfIn PDF document text
    • http://alt-1c.ru/userfiles/file/vuduxogof.pdfIn PDF document text
    • https://ambientltg.com/wp-content/plugins/super-forms/uploads/php/files/de7b97bce5ae0ecc0f3770efa3570769/kumepizomiw.pdfIn PDF document text
    • https://lsp.od.ua/wp-content/plugins/super-forms/uploads/php/files/qt4peo1lel690kaf90r1i7t3d6/gutekenosejikafuwone.pdfIn PDF document text
    • http://beautybybelief.com/admin/images/file/sokivisivexumumemubapa.pdfIn PDF document text
    • http://kinel-hunter.ru/upfiles/file/86393392889.pdfIn PDF document text
    • http://autoklej.pl/app/webroot/media/files/wimafibebol.pdfIn PDF document text
    • http://gdgom.com/upload/file/2106200942074315557klev35mi69i.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=behaviorism+philosophy+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_off0000da87.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA87 10792 bytes
SHA-256: bfadc8794e7d638a83583e41cf5af6a6c9c66aea2708ab9a15e333350b381904
font_01_sfnt_off0000f36d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF36D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010b7f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B7F 18000 bytes
SHA-256: 7622a53ef4a4981d9672f9e0e00abd0f9cda6e85235e9e67b8a4b1e13b05e787