Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a6421e16d67951e…

MALICIOUS

PDF

81.9 KB Created: 2021-09-03 22:29:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 925dd8d4669cfcbf15f9fe3ca875e993 SHA-1: 250204bc66525df9da2051a63abd4bb0d1d53205 SHA-256: 5a6421e16d67951ed4cd003f8f784c1f11b8513e400205955557229b7b3043e8
156 Risk Score

Malware Insights

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

The PDF contains a large number of links, many pointing to compromised WordPress sites, indicating it functions as a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the structure and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

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://hydratrend.com/application/third_party/ckfinder/userfiles/files/jowilonarexuzufaporex.pdf In PDF document text
    • https://ceadersvalet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c162f61953c---talawopas.pdfIn PDF document text
    • https://winston-woodward.com/wp-content/plugins/super-forms/uploads/php/files/b8b7e92d06f083dedae1ebf61e1a7b38/79640522689.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/9fec09e850eaf691c946e2db3685958e/67243197211.pdfIn PDF document text
    • https://mebelpozakazu.ru/wp-content/plugins/super-forms/uploads/php/files/30a033116250662395bf15bcc0161095/99362314822.pdfIn PDF document text
    • http://swissies.lt/ckfinder/userfiles/files/62985937831.pdfIn PDF document text
    • https://www.criteriainvest.com.br/wp-content/plugins/super-forms/uploads/php/files/7mtmp3fmib33bo92ds1h7r92lo/75975188583.pdfIn PDF document text
    • https://museuminiaturesbesalu.com/files/sirotefupebadinaridak.pdfIn PDF document text
    • http://sbs-group.co/userfiles/files/4839868683.pdfIn PDF document text
    • http://thaicockstar.com/ckfinder/userfiles/files/35502226372.pdfIn PDF document text
    • http://amadpich.com/userfiles/file/xuwazalepufawisizuf.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16079e756a426f---bezaxetopesawedese.pdfIn PDF document text
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/fhnursrkj2gfic6qpf21s4kal0/biwufemularolafebigu.pdfIn PDF document text
    • https://siyata.co.il/wp-content/plugins/formcraft/file-upload/server/content/files/16080b85ad3903---nuwaduro.pdfIn PDF document text
    • https://assurancemauricie.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608267fa2e77c---1104693552.pdfIn PDF document text
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f080f9d5c0---jevudegujesuxu.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/160917b3c01e08---9819670715.pdfIn PDF document text
    • https://balaji-technology.com/userfiles/file/tadas.pdfIn PDF document text
    • http://ri-rm.ru/userfiles/file/zirip.pdfIn PDF document text
    • http://accessiblevehicleservices.com/userfiles/file/91328952379.pdfIn PDF document text
    • http://peneleos.pl/userfiles/file/58237658535.pdfIn PDF document text
    • http://zrdb-drogbud.pl/Upload/file/pabijeselokozapumu.pdfIn PDF document text
    • https://www.hediyevideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609183bcdfd47---pujutin.pdfIn PDF document text
    • http://sport-way.ru/img/file/sirosaxut.pdfIn PDF document text
    • https://www.apartamentselsllacs.com/wp-content/plugins/super-forms/uploads/php/files/0nfv2qdm3b6ihp9b5uel9qh9tl/70034863721.pdfIn PDF document text
    • https://www.mixedclass.com.au/wp-content/plugins/super-forms/uploads/php/files/vqc9hbtpiusp5g2kooqi49n0r2/11638176800.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=water+pressure+relief+valve+pdfPDF 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_off0000dc96.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC96 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f4a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4A8 17376 bytes
SHA-256: 10334f614724c5f6edf98658dceb5583e9b4c3c91fdc641d57dc617e519cd1f2
font_02_sfnt_off000121d0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121D0 10424 bytes
SHA-256: 248ba6804b3fca2a91f2ee5d89af2b2ab9ebcfa528bdcfc2635dbdeb9b77955f