Malicious PDF — malware analysis report

Static analysis result for SHA-256 e5db49c286589ec9…

MALICIOUS

PDF

71.5 KB Created: 2021-06-24 21:53:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 143bc6791e9e7d169387bd52c36a7725 SHA-1: 94bec9df3cde4e3a4944f98146d311d3292e3ee0 SHA-256: e5db49c286589ec9aa61027a48474765ac8c0438e0bd11d94fe6a2ed4011cdb5
156 Risk Score

Malware Insights

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

The PDF file contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, suggesting a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly indicate malicious intent, likely related to phishing or malware distribution, masquerading as an answer key.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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://cructi.ru/uplcv?utm_term=answer+key+of+10th+maths PDF link annotation
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/c73506086c0494f002099a04d39e866d/7347451079.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/b46075c929254ce82321a41d3cfcd657/76854711559.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aebae4703e3---74755560972.pdfIn PDF document text
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a1336401cc4---25554100048.pdfIn PDF document text
    • https://efficimm.fr/userfiles/files/nomoxudeguf.pdfIn PDF document text
    • http://jhsclassof63.com/clients/c/c8/c8cc7cee7579ddcd469b669c0eb172d8/File/latejuwopagunadibo.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ba4a62cbaaf---27148672369.pdfIn PDF document text
    • https://mn-lawfirm.com/box/userfiles/file/wokudofamev.pdfIn PDF document text
    • https://eduinfinite.com/wp-content/plugins/super-forms/uploads/php/files/15a9e35be49fc84d4e5a23c4e9a988c7/14642201270.pdfIn PDF document text
    • https://tirthmobile.com/wp-content/plugins/super-forms/uploads/php/files/1lj8eq929o8uer1viarh2fb4d3/90174443068.pdfIn PDF document text
    • http://paintingservicesonline.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1609401460c099---10054470400.pdfIn PDF document text
    • https://qboardapp.com/wp-content/plugins/super-forms/uploads/php/files/813266a612fff9d71feb278a668fdb61/vafixoxikejelaxeguwur.pdfIn PDF document text
    • https://www.demetagras.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f1c5076aac---99904059399.pdfIn PDF document text
    • http://www.brennholz-heinlein.de/wp-content/plugins/formcraft/file-upload/server/content/files/160833012405ed---nukivigivudemaro.pdfIn PDF document text
    • https://theshairpodcast.com/wp-content/plugins/super-forms/uploads/php/files/f095ca9c360f39f1fe1be8f3c8781106/286691730.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d9e0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9E0 5416 bytes
SHA-256: b6743d96ec47d77c74de9b10b9dbaa6bf3efba962b69cbec5a934af12021c07c
font_01_sfnt_off0000ec41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC41 10888 bytes
SHA-256: f733b7c781e970a3938fdc01252a2d96cf8081a00763b1463b438f3c6986225c