Malicious PDF — malware analysis report

Static analysis result for SHA-256 3d439b6b54006cfd…

MALICIOUS

PDF

79.5 KB Created: 2021-09-09 02:37:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: ba88a1edde868e8c64aba14fd222812d SHA-1: 83f371c3b3631e8b21636d6b1ad0c6ff53071c45 SHA-256: 3d439b6b54006cfd865c0ebebb8aaaa90a6ce54569d38a44d2278898b054a582
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file is identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to external sites, with several hosted on compromised CMS platforms. The presence of a 'link farm' heuristic and multiple unknown URLs suggests an attempt to lure users to malicious destinations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://cauthinh.com/luutru/files/46169294863.pdf In PDF document text
    • http://www.integra-cr.cz/administrace/ckfinder/userfiles/files/92661216201.pdfIn PDF document text
    • http://llux.vn/uploads/files/67358027309.pdfIn PDF document text
    • https://pianoinprimopianofestival.com/uploads/file/42992844357.pdfIn PDF document text
    • https://hung168.tw/UserFiles/files/68345693240.pdfIn PDF document text
    • http://greenhousehotel.vn/uploads/image/files/saniwomisuregu.pdfIn PDF document text
    • https://dananeye.com/uploads/files/202109042301395098.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/161368797dad45---mufujiwo.pdfIn PDF document text
    • https://proartgaleria.hu/files/files/24599888626.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161394135c5be6---pogikofikibufewem.pdfIn PDF document text
    • http://the-bom.kr/upfile/files/nukapitoramufarinurutapa.pdfIn PDF document text
    • https://loyalangkorapartment.com/userfiles/file/zomasuzuzotivepem.pdfIn PDF document text
    • http://fw-simple.com/uploads/files/12346805943.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/98568569171.pdfIn PDF document text
    • http://phupmirpol.pl/userfiles/file/rujewibegopa.pdfIn PDF document text
    • https://sandipkumardutta.com/ckfinder/userfiles/files/5115395271.pdfIn PDF document text
    • http://fd-health.com/upload/ckeditor/files/musuzunedojozumobuwiro.pdfIn PDF document text
    • http://nelly-design.ru/upload/files/3836079387.pdfIn PDF document text
    • https://regenerateacademy.com/file/kazediwomamitumet.pdfIn PDF document text
    • http://cherryontop.pl/upload/fotki/file/59215704435.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/2261024b621c302c6a0ad1b90d0aa887/51551843773.pdfIn PDF document text
    • http://exteractif.fr/pictures/2/rupulefizonotogu.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/27954174360.pdfIn PDF document text
    • http://abwclayton.com/uploads/files/sipasudemoniterexebenoru.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=download+song+uptown+funkPDF 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://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_off0000d263.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD263 17604 bytes
SHA-256: 213759a5d4130254ac82503e3e30db223bdd960eecd473119216a51ddb190057
font_01_sfnt_off00010015.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10015 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001182c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1182C 10628 bytes
SHA-256: c0a7ff9c6d95114e6514ccf7dd1eee99aee934a5b4394d09e2b641a54828f3e3