Malicious PDF — malware analysis report

Static analysis result for SHA-256 51fa6a5f4b46a94f…

MALICIOUS

PDF

79.3 KB Created: 2021-09-20 08:37:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d4863dc69671463f41d00ed75ed5d5ac SHA-1: dc432977e9fd6866b0dd313fba58cb07977f38c6 SHA-256: 51fa6a5f4b46a94ff8e7d0a81e2d3c1701f32ea6e0a8f342952a1975aec5c394
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are part of a link farm designed to redirect users to other sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The presence of a 'download button' heuristic further supports the lure-based attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://rosycaffe.com/file/zozoduxamokezulemugub.pdf In PDF document text
    • https://festivaldelmaridaje.com/sgi_userfiles/userfiles/files/8216061135.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613d3d0d750f0---dekusuluturosubolir.pdfIn PDF document text
    • https://firmabudowlanawalczak.pl/web/uploads/files/wekusavolexabu.pdfIn PDF document text
    • http://filipdegreef.be/uploads/files/78342583364.pdfIn PDF document text
    • http://pataibicaj.hu/userfiles/file/xilusonowepufupesenijeda.pdfIn PDF document text
    • http://kraljicabih.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613cf344c91a9---99067004558.pdfIn PDF document text
    • http://xn--80aagkbrca3apkgkee0a1bi.xn--p1ai/ckfinder/userfiles/files/56674289837.pdfIn PDF document text
    • https://hitourkorea.com/FileData/ckfinder/files/20210901_1D5287B609396460.pdfIn PDF document text
    • https://vico-real-estate.com/ckfinder/userfiles/files/6521823603.pdfIn PDF document text
    • http://rhondadejean.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/75240272621.pdfIn PDF document text
    • https://sssmri.com/ckfinder/userfiles/files/77095071524.pdfIn PDF document text
    • http://salman-is.com/userfiles/file/jufuma.pdfIn PDF document text
    • https://nevisnews.com/userfiles/7399333818.pdfIn PDF document text
    • http://kleinschadenexperte.com/userfiles/file/13994846104.pdfIn PDF document text
    • http://uniondrygoods.com/fckeditor/userfiles/file/ruxativuzotaboseguk.pdfIn PDF document text
    • http://selfmadefilms.nl/userfiles/files/tutuwejeja.pdfIn PDF document text
    • http://vngo-cc.vn/cooker/public/files/vabilafodufuzowesofapanav.pdfIn PDF document text
    • https://mepho.hu/ckfinder/userfiles/files/pigetizasarovawixejip.pdfIn PDF document text
    • http://monkey-do.net/userfiles/file/beruvixilevutetuvonag.pdfIn PDF document text
    • https://chingchia.com/uploads/files/202109112323201786.pdfIn PDF document text
    • http://herborgthailand.com/file_media/file_image/file/73441388453.pdfIn PDF document text
    • https://motiwalainstitutes.org/userfiles/file/74869159474.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=convert+exe+to+apk+onlinePDF 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_off0000d28e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD28E 10368 bytes
SHA-256: 01ecb04857cc54954ca25df5185907ab1e812c8684df5cc103d009e310b708f7
font_01_sfnt_off0000ea24.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA24 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010236.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10236 17444 bytes
SHA-256: fbfe123ea26f2f11d6957d57137b4df2993d711ebe12df065104d2e5bdb2f5ac