Malicious PDF — malware analysis report

Static analysis result for SHA-256 5206858a2198e785…

MALICIOUS

PDF

75.8 KB Created: 2021-09-06 11:18:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: ba541bda83f2d7be2aeeaf955e3ff9f8 SHA-1: f5be38c6cf275933fac9ddade4451df97c18c417 SHA-256: 5206858a2198e785c4a5f9b4dd192791b2745e476b01a82f323e5775cfed921c
156 Risk Score

Malware Insights

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

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. Static analysis revealed it functions as a link farm, with numerous URLs pointing to compromised WordPress uploads and disposable hosting sites. The embedded URLs are designed to redirect users, likely to phishing or malware distribution sites, aligning with a spearphishing attachment attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.oschouston.com/osc/wp-content/plugins/formcraft/file-upload/server/content/files/160ae68557e801---nobegapit.pdf In PDF document text
    • https://beautyyaurient.com/editor_upload/file/tosasexe.pdfIn PDF document text
    • http://wenyanchem.com/upload/files/76083632616.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021070211163152.pdfIn PDF document text
    • http://valsadindustries.com/userfiles/file/37574965011.pdfIn PDF document text
    • https://gyn-koe70.de/obrazky/file/dojazitokexelaxagupo.pdfIn PDF document text
    • http://studiocariola.com/userfiles/files/gobizeril.pdfIn PDF document text
    • https://tcufroghouses.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ce59c387b5---rimigotimumeke.pdfIn PDF document text
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/26db0327fb043332f3e1ff9193e0ef14/46413295598.pdfIn PDF document text
    • https://eltonltd.ru/sites/default/files/uploads/41241703739.pdfIn PDF document text
    • https://beribuket.ru/wp-content/plugins/super-forms/uploads/php/files/ea57f909dde842e1714fede366538a7f/23481657970.pdfIn PDF document text
    • https://pingthye.com/userfiles/files/34014697123.pdfIn PDF document text
    • http://hometextiles-consultant.com/ckfinder/userfiles/files/vizivarosal.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607689897b206---fusofebipazukapimatevira.pdfIn PDF document text
    • https://wita.lt/images/files/lupakufones.pdfIn PDF document text
    • http://wasserburg.pl/userfiles/file/93247281526.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607469174ffef---mevadekadidawizo.pdfIn PDF document text
    • http://tramtronbetong.com/uploads/userfiles/file/ruvadadatagorigalulerolig.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ddb379a3417---86140317347.pdfIn PDF document text
    • https://apexforestservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a57186bf8ed---babezipukiw.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/4d772607583b9e05cd243cf9dbc7c856/4534975568.pdfIn PDF document text
    • https://endoaccessories.com/wp-content/plugins/super-forms/uploads/php/files/fratvud3ucgbfvngf846p9soui/24449241691.pdfIn PDF document text
    • https://www.scilights.com/wp-content/plugins/super-forms/uploads/php/files/9e4e275a9179e28977137bac1be24643/fovejoluxutijevuxufokume.pdfIn PDF document text
    • http://www.klpreschool.com/wp-content/plugins/formcraft/file-upload/server/content/files/160977117cad3b---fuwotig.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+make+chrome+default+pdf+viewer+windows+10PDF 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_off0000c1bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1BB 17644 bytes
SHA-256: 43239bc73e7d48ed927daa105e67fe772e6d91adbe8587187bf63973a62297b6
font_01_sfnt_off0000ee91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE91 11396 bytes
SHA-256: adc2017e47bebcbd74dccd091191e6132b89e999ce0d167f32b264a31119a080
font_02_sfnt_off0001094e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1094E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1