Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8d98cbf2877b6ec…

MALICIOUS

PDF

85.9 KB Created: 2021-09-08 15:11:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 85ff84478cf88fe108fb15a981c85078 SHA-1: 5e026550e439ead3e186a24bc3563d9ce31fe26e SHA-256: b8d98cbf2877b6ec195c2f6006494b9df65141dd73a1dd292bd97d47df319596
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links pointing to potentially compromised or disposable hosting sites, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. While no scripts were explicitly extracted, the PDF structure and link farm heuristics point towards an attempt to redirect users to malicious content, likely involving embedded JavaScript.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9912

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
  • 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 http://dulwichtaxi.com/survey/userfiles/files/39070233210.pdf In PDF document text
    • http://labonscafe.com/userfiles/9850091028.pdfIn PDF document text
    • https://cosmopolitanhotel.eu/uploads/wysiwyg/files/kaselopaxoseno.pdfIn PDF document text
    • https://vegas-shop.net/uploads/files/30360601942.pdfIn PDF document text
    • https://ev-owners.jp/userfiles/files/84704823159.pdfIn PDF document text
    • http://visualpaint.com/wp-content/plugins/formcraft/file-upload/server/content/files/16134265f5075f---68972440920.pdfIn PDF document text
    • https://bushregenerators.net/userfiles/files/tatowimovuvo.pdfIn PDF document text
    • https://chameleoncoupons.com/adgprocessing/uploads/files/35803426026.pdfIn PDF document text
    • https://xn--90aoja6ahg5ds.xn--p1ai/uploads/files/60643344868.pdfIn PDF document text
    • http://quangcongluc.com/upload/files/wisuxodenodusi.pdfIn PDF document text
    • http://euro520.net/userfiles/file/16308799471717485090.pdfIn PDF document text
    • http://sjar-tech.com/uploadfile/file///2021090800001128.pdfIn PDF document text
    • https://comptables-publics.fr/userfiles/file/7845103535.pdfIn PDF document text
    • http://0975811252cool.linker.tw/files/mapofoga.pdfIn PDF document text
    • https://doluhosting.com/calisma2/files/uploads/gosilafaluwa.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/25705315452.pdfIn PDF document text
    • http://mecateengenharia.com.br/ckfinder/userfiles/files/1715211878.pdfIn PDF document text
    • http://studiorinaldibedin.eu/userfiles/files/netir.pdfIn PDF document text
    • http://canphantich.net/Images_upload/files/25774605242.pdfIn PDF document text
    • http://compie.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161382604411c9---molazezitusijudux.pdfIn PDF document text
    • http://gediklimakinahidrolik.com/resimler/files/xaluk.pdfIn PDF document text
    • http://kingkady.com/uploadfile/files/54630822016.pdfIn PDF document text
    • http://lungshingcentre.com/userfiles/figiv.pdfIn PDF document text
    • http://ljhalls.com/wp-content/plugins/super-forms/uploads/php/files/99d4aa30728cc44ef868ccc484a07888/bimutikezu.pdfIn PDF document text
    • https://theatresaucinema.fr/uploads/file/lixususuretijumizorivilik.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/161305b5083022---41820623137.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=physics+momentum+and+impulse+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_off0000e594.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE594 11000 bytes
SHA-256: 3b0602afe774e44c0bb9efabcd738c7fcc16f5c10aab37f2b58f9e9f276f6465
font_01_sfnt_off0000fefe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEFE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011710.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11710 19140 bytes
SHA-256: f1d9020d88d3335620b6648ace5141e8e05ddd491a67105044cebb90f6a185e8