Malicious PDF — malware analysis report

Static analysis result for SHA-256 737635f7e81d643f…

MALICIOUS

PDF

68.6 KB Created: 2021-05-02 03:59:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-23
MD5: f733798f2747dd9c1f0886eb2c40083e SHA-1: 731c3b924e0eba3f2035c5d5cae5bbc5adf079dc SHA-256: 737635f7e81d643f0b6535c112f4ab526f9c7055a61b324492403a0e7c8859cb
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The document contains a link farm pointing to compromised WordPress upload storage, suggesting it's designed to redirect users to malicious content. The presence of numerous links on disposable hosting further supports a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/99ba03747147e90d2c1bbda641a91813/66077506016.pdf In PDF document text
    • http://www.segurosfacility.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160830513e877c---betojigomujanegeburuxafa.pdfIn PDF document text
    • http://barrarioservicos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606f395323e69---sesusanivaruboj.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d43e293072---5507096227.pdfIn PDF document text
    • http://www.fattyweng.com.sg/wp-content/plugins/formcraft/file-upload/server/content/files/160776472c4c93---35868601428.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608925ed22629---rijekakedomukuxozaduja.pdfIn PDF document text
    • http://www.asejnrtigers.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16075849c064cb---57258542500.pdfIn PDF document text
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/933g5n408gosgti08oivodlsmg/50810144455.pdfIn PDF document text
    • https://pfgmm.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1607de1f88672b---mejopofevonibegijix.pdfIn PDF document text
    • https://big-cash.de/wp-content/plugins/super-forms/uploads/php/files/1ierlnpq954nlr56hdm403i2g9/2220642917.pdfIn PDF document text
    • https://refour.eu/wp-content/plugins/super-forms/uploads/php/files/d228d14938b5b06838b4b759f95986b4/45398707093.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/r04bmkoidf7q7rafmi0vkn97ur/zenukuwapudaliri.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160796614128e2---rikutaxawotibabob.pdfIn PDF document text
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c1da25b12a---88315285745.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/85b2452ef242431d9e46557a83cdd801/badozufarazig.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=characteristics+of+good+research+topic+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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d25a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD25A 5292 bytes
SHA-256: dcff7320c05002b867f123c03e35d811a9285d6d9e6461ae0c1334c1f3c93d14
font_01_sfnt_off0000e44e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE44E 9608 bytes
SHA-256: 68c2a5c06c0e5aeec6279b44273d5bfc74c80d47a5e04e00abbd02e2e09cb5dc