Malicious PDF — malware analysis report

Static analysis result for SHA-256 efff1060d3d3f6df…

MALICIOUS

PDF

77.3 KB Created: 2021-09-21 15:11:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 40c7c73e79509d536c88cda51d3424b8 SHA-1: 8990fdcfbe4c1bf156498325d2f1ba1cb65308ab SHA-256: efff1060d3d3f6dfdf7c9fdbe60df166e0a118e8dd36f1418e3af6b11ae67027
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It functions as a link farm, containing numerous embedded URLs that point to other PDF files hosted on various domains. This suggests an attempt to lure users into downloading further malicious content or visiting phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

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 https://laborke.ru/uplcv?utm_term=balancing+redox+reactions+worksheet+1 PDF link annotation
    • http://ecompletecontact.com/ckfinder/userfiles/files/5291635584.pdfIn PDF document text
    • http://www.malagatour.es/ckfinder/userfiles/files/rotefujotebilolukomerab.pdfIn PDF document text
    • https://ferado.vn/userfiles/file/4115589107.pdfIn PDF document text
    • https://xn----8sbaavnccwq4am.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/4bc5a7b56bb5105e156eb28134698fa5/44555042593.pdfIn PDF document text
    • http://brcassociati.com/userfiles/files/83558523847.pdfIn PDF document text
    • http://gramercygrand.ru/files/file/xidoniwinipaxegagaripa.pdfIn PDF document text
    • http://akkoryazilim.com/userfiles/file/buxegir.pdfIn PDF document text
    • http://asirakademi.com/resimler/files/5122557130.pdfIn PDF document text
    • http://vers-ma.de/userfiles/file/20141378836.pdfIn PDF document text
    • http://sreema.org/FCKeditor/file/91589736690.pdfIn PDF document text
    • http://thepokeluau.com/uploads/files/pimozebebeb.pdfIn PDF document text
    • http://phulieumaymacbaoco.com/hinhanh_fckeditor/file/95821563308.pdfIn PDF document text
    • http://www.greddy.com/admin/common/ckfinder/userfiles/File/81595516170.pdfIn PDF document text
    • http://gpsputhuppally.com/userfiles/file/numejimetugelagupuj.pdfIn PDF document text
    • http://parentini.it/userfiles/files/lobujotulixulotarix.pdfIn PDF document text
    • https://www.ideaklinikbakirkoy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b927172d59---lutowosubusutowu.pdfIn PDF document text
    • https://zemiigori.com/uploads/file/sejosifinoduzew.pdfIn PDF document text
    • http://peter-scherer.de/userfiles/file/xoxumezaruzugez.pdfIn PDF document text
    • https://studioconcept-stand.com/fck_userfiles/file/70713837427.pdfIn PDF document text
    • http://cbestdesign.com/ckfinder/images_store/files/rekijimuvogibipubopavo.pdfIn PDF document text
    • http://jubileejec.com/userfiles/files/45997004883.pdfIn PDF document text
    • http://tuvanluatdanang.com/upload/ck/files/40812473544.pdfIn PDF document text
    • http://eau-msu.ru/ckfinder/userfiles/files/45017499549.pdfIn PDF document text
    • http://vivo-mebel.ru/upload/file/telokigirapajozifimijap.pdfIn PDF document text
    • https://madspot.dk/ckfinder/userfiles/files/wewaruzi.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_off0000c651.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC651 11036 bytes
SHA-256: b74c0ce00ab22d10a1604baedb3f6593cff71556321d3ce525e81f5fd8dc6fdf
font_01_sfnt_off0000dfdd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFDD 18464 bytes
SHA-256: cec85dd534bb54fc87133a47bd265984b6f82a584f8cecee4f47483f669ade0e
font_02_sfnt_off00010fba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10FBA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1