Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c835a1fe0e322ac…

MALICIOUS

PDF

102.6 KB Created: 2021-06-15 17:36:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-04
MD5: b757b187ab7d926d9ed4c48f5f52c85f SHA-1: f3b6ae5d34987eb08bba92b0dcfb8d60bef5fbe4 SHA-256: 8c835a1fe0e322ac5087446ee0a577eece01300491c2aa57f70ff9bada4ae60f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://cructi.ru/uplcv?utm_term=sentence+in+simple+future PDF link annotation
    • http://galluccifaibano.com/userfiles/file/danurowikugewixarituwimeb.pdfIn PDF document text
    • http://unnatiwelfareorganization.com/ckfinder/userfiles/files/wexopomezukuzofanamu.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075fddb06702---zewinipivoto.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/987d4dd221639f44cbc11b79b7778a29/27953694368.pdfIn PDF document text
    • https://actioncoach.com.my/wp-content/plugins/formcraft/file-upload/server/content/files/160b41e3aeba41---jegivofi.pdfIn PDF document text
    • https://picinterior.com/ckfinder/userfiles/files/tawanenujixawuditejoxuf.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/33757f36cf05201f1de0a174a0f41226/82986927380.pdfIn PDF document text
    • https://bestcoloringpages.com/userfiles/file/85438232639.pdfIn PDF document text
    • https://hgb.se/filer/file/tutiwakujo.pdfIn PDF document text
    • https://cosplay-expo.it/ckfinder/userfiles/files/xofomotagol.pdfIn PDF document text
    • https://migger.dk/userimages/file/50929070529.pdfIn PDF document text
    • http://dolphinegypt.net/userfiles/file/51421374423.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://kioskcondoweb.wpengine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608428c282613---37765047899.pdfIn PDF document text
    • 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
    • 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_off00013e42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E42 5052 bytes
SHA-256: 10d988be4598c0a88d5342434d8dcb2bdb91a84ffa388c4fadcdc88c68e5de68
font_01_sfnt_off00014f64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14F64 11748 bytes
SHA-256: d4a38558d78b6f26197c124e5fb18ce7e13f0065a2b838c95ee9c4bf818ec1dc
font_02_sfnt_off000176f1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x176F1 16544 bytes
SHA-256: c64f975c7c74378765a15e192890ba001b575443647995d4109c17b56814fb1e

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