Malicious PDF — malware analysis report

Static analysis result for SHA-256 351f87cef6a85387…

MALICIOUS

PDF

80.8 KB Created: 2021-09-20 07:03:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 286083b9819907e8be24d173b0abeec3 SHA-1: 1f6260ca158436bec535423cc7b72d8179f16795 SHA-256: 351f87cef6a8538792a640ccf30d7eddfc2807115320a6acaeda7cb9f7d71e94
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The PDF contains numerous embedded URLs, with one heuristic specifically identifying it as a link farm on disposable hosting, suggesting a phishing or redirection scheme. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of an attempt to lead the user to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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 http://www.pratikchoudhury.com/fckimages/file/52065935359.pdf In PDF document text
    • https://www.gpaci.org.br/cms/ckfinder/userfiles/files/31998338240.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613ab9fcc4a0f---rizebubexegeraxopagefo.pdfIn PDF document text
    • https://7foro.exceltur.org/exceltur_nuevo/ckfinder/userfiles/files/tiloso.pdfIn PDF document text
    • https://adeptos.clevercloud.pt/images/items/files/mozogizemifafew.pdfIn PDF document text
    • http://pferdefreunde-brueckenhof.de/sites/default/files/userfiles/file/78143478438.pdfIn PDF document text
    • http://acelybio.com/upload/files/rejademelinovezote.pdfIn PDF document text
    • https://aurorabersinar2.com/contents/files/leguzudozinarezon.pdfIn PDF document text
    • http://koreabulk.net/userData/board/file/97643931832.pdfIn PDF document text
    • http://atlonnuri.org/UpLoadImage/editer/files/vitetigimitebefitow.pdfIn PDF document text
    • http://metafelix.it/userfiles/files/lobanawawodog.pdfIn PDF document text
    • http://teacherandtraining.com/coj_u/KK/userfiles/files/65198681416.pdfIn PDF document text
    • http://alnadaoil.com/userfiles/file/64624185287.pdfIn PDF document text
    • http://donauwell.at/userfiles/file/vobagenuteluxuwaba.pdfIn PDF document text
    • http://sunmoon-glory.com/web/upload/files/28721138569.pdfIn PDF document text
    • https://tinhhoaxanh.vn/userfiles/file/pozigo.pdfIn PDF document text
    • https://pre-www.bridge-college.com/uploaded/ckeditor/files/70486941089.pdfIn PDF document text
    • http://soosanfix.com/upload/fckeditor/file/toxitizulokap.pdfIn PDF document text
    • http://eatoceanic.iorderfoods.com/uploads/files/lutetedibodemile.pdfIn PDF document text
    • https://sakesushimn.com/userfiles/files/ganopamo.pdfIn PDF document text
    • https://shoppingplanet.ro/ckfinder/userfiles/files/69363216462.pdfIn PDF document text
    • http://aotwresort.org/ckfinder/userfiles/files/76566268757.pdfIn PDF document text
    • https://norservis.com/files/files/53702610753.pdfIn PDF document text
    • https://motty-etai-sharon.com/files/files/faraxipifepimoxejufex.pdfIn PDF document text
    • https://htfcompact.com/wp-content/plugins/super-forms/uploads/php/files/54d2d0e56ab4993aee7a8b67a6e1907c/kutajirerobalebud.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/S30rS-6n6vg/uplcv?utm_term=how+to+get+into+peoples+snapchatPDF 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_off0000d736.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD736 17632 bytes
SHA-256: ace2b64656f5064851f77c7c4dbc0189c7000295043936d4a1c07b2c51e05b6d
font_01_sfnt_off000104cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104CB 10632 bytes
SHA-256: 63f73971e8f21ae4c1a5317d34c81f169e991ba14d0a3d523b42b8bc8e11e3cd
font_02_sfnt_off00011d1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D1D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1