Malicious PDF — malware analysis report

Static analysis result for SHA-256 540f1781b472bb0a…

MALICIOUS

PDF

81.8 KB Created: 2021-09-18 10:21:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 93ace8029615099bb285b6d1e860b6f4 SHA-1: f7c94c2acd1d816f9c8b24daa4aebc31d129a219 SHA-256: 540f1781b472bb0ab7b86cd01ca42315e1d36c63cfbdc41a0e6e3cd059aefc18
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it's a link farm pointing to compromised WordPress uploads and disposable hosting. The PDF contains numerous external URIs, suggesting a phishing or malware distribution lure. No scripts were extracted, but the presence of external links is a strong indicator of malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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=fast+%26+furious+7+full+movie PDF link annotation
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613460ab38910---seleguze.pdfIn PDF document text
    • http://mintaialuminum.com/d/files/baxapiz.pdfIn PDF document text
    • http://www.kocay.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1614171342630a---tinaruziwenex.pdfIn PDF document text
    • http://bestorkate.com/uploads/ckeditor/files/68296661552.pdfIn PDF document text
    • http://chingyi.tw/userfiles/files/bisurisomajofeledoterejuv.pdfIn PDF document text
    • https://kocarbonag.com/luutru/files/58712261233.pdfIn PDF document text
    • https://grandhotelushba.com/userfiles/file/86980431567.pdfIn PDF document text
    • https://goodline.by/userfiles/file/luvosarekijimulutes.pdfIn PDF document text
    • http://ozt.zielonetarasy-cieplice.pl/uploads/userfiles/files/37438925926.pdfIn PDF document text
    • https://toskov-yordanov.com/userfiles/file/52496620306.pdfIn PDF document text
    • http://hitecds.com/userfiles/file/lixafuku.pdfIn PDF document text
    • http://e-sportis.com/images/upload/kerinude.pdfIn PDF document text
    • http://aven.su/userfiles/file/83842554544.pdfIn PDF document text
    • https://wurstfargo.com/wp-content/plugins/super-forms/uploads/php/files/0425d4d7b8ea869f54dbfcf821dd9cc9/25856668188.pdfIn PDF document text
    • http://goldnumber.info/userfiles/file/wuvutalumovuz.pdfIn PDF document text
    • http://pwr-tech.ru/userfiles/file/28306668510.pdfIn PDF document text
    • https://ruxthai.com/ckfinder/userfiles/files/demitexakipuzokuvi.pdfIn PDF document text
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/c85f8791f6a0644ca95cdf9af6c55bf2/4426733253.pdfIn PDF document text
    • http://iwayman.com/uploadfiles/file/210915143529212095b8pjfa.pdfIn PDF document text
    • http://kimyasaldubeller.com/upload/ckfinder/files/97157938103.pdfIn PDF document text
    • http://licausi.it/userfiles/files/89089671836.pdfIn PDF document text
    • http://www.ponderosafestival.com/wp-content/plugins/formcraft/file-upload/server/content/files/161423c2d64f26---keridix.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://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_off0000d9dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9DC 19844 bytes
SHA-256: a723e47a399f8919baac48debd4065004a2f8d0e05075e1d33cad5ba88a21c6f
font_01_sfnt_off00010d3e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10D3E 9476 bytes
SHA-256: f51d5d1ed6f87b52d1b9f429dd51402bf3eddb0f0727a485d5a13d2cfa109c79
font_02_sfnt_off000121a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1