Malicious PDF — malware analysis report

Static analysis result for SHA-256 31dda766b2b78472…

MALICIOUS

PDF

86.1 KB Created: 2021-06-24 00:53:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-17
MD5: 6f0d39583f5f00fe0e89ff04e62b0115 SHA-1: 130a331058f2f9ea3db08e2423cc3b30843d7be5 SHA-256: 31dda766b2b784720b593e3c2f86be77265174682cfd50283419231aed2da4bc
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The file functions as a link farm, directing users to various compromised WordPress sites, likely to download further malicious payloads. The embedded URLs and the heuristic findings suggest a phishing or malware distribution scheme disguised as a free download for educational materials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9644

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
  • PDF differential parser failed info PDF_DIFFERENTIAL_PARSE_FAILED
    The cross-check parser (pdfminer.six) failed on this file: PDF differential parser failed: PDFSyntaxError. Static heuristics still ran and any of their findings above are valid; only the differential cross-check signal is missing.
  • 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://ketchas.ru/uplcv?utm_term=maths+notes+for+class+11+pdf+free+download PDF link annotation
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072a3c73055c---sabemikowodaruw.pdfIn PDF document text
    • https://mithermomix.com.mx/wp-content/plugins/super-forms/uploads/php/files/7b626430918e483210c127cc00f7f330/49639392354.pdfIn PDF document text
    • https://sg-design.top/wp-content/plugins/super-forms/uploads/php/files/30a2cc94887aceba795289677c0ab522/72707664945.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ae43931ae42---81450323424.pdfIn PDF document text
    • http://thefutureofgolf.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160879406a78f9---60606902798.pdfIn PDF document text
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/569abcdd632322d3031de248ce0eabaa/31086609426.pdfIn PDF document text
    • http://brilspa.ro/userfiles/file/%5C/sinazavusodixaferubato.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086e098d40fe---batumezuzixaropemaperew.pdfIn PDF document text
    • https://www.marbelitesa.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16070661571c89---muximavogefozu.pdfIn PDF document text
    • https://asthasupermarket.com/userfiles/file/bafatosobu.pdfIn PDF document text
    • http://miroslaws.com/ckfinder/userfiles/files/13243950527.pdfIn PDF document text
    • http://redigonda.it/userfiles/files/24371382690.pdfIn PDF document text
    • http://asesorgubernamental.com/images/file/beludemejuremajugiw.pdfIn PDF document text
    • http://aldara-latinoamerica.com/userfiles/file/41860592608.pdfIn PDF document text
    • http://smc.org.in)MeeraRegularMeera2016SMC7.0.0+20171102HussainIn PDF document text
    • http://smc.org.inhttp://smc.org.inIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://gitlab.com/smc/meera/blob/master/COPYINGIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_003_off0000ed41.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0xED41 19084 bytes
SHA-256: f6964c361cc93e818004abf4c691cd6b647b21d41ae058515a6bb6707862679c
font_00_sfnt_off0000dbcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBCC 5132 bytes
SHA-256: 4c3e9797adf70dfdff88ee3158ad61bbc52014737c499dcca92623c62ccaad1d
font_02_sfnt_off00012603.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12603 10744 bytes
SHA-256: fca7bf45e268b1a0d063db188d92b13d5efed56582f5b031ac2defc66390e493
font_03_sfnt_off00014aa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14AA4 4324 bytes
SHA-256: d1f4a20f0e35a0564be54678b929bb8c711862c507f070c2b9a6abea8daf4378

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