Malicious PDF — malware analysis report

Static analysis result for SHA-256 257f79c0789b37b6…

MALICIOUS

PDF

83.6 KB Created: 2021-09-04 13:25:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 7f087dc82f38cc63ea42f4ddc73f924d SHA-1: 1442d69e1b374e7c207d098600d0db983f05974a SHA-256: 257f79c0789b37b6d9b2a70ec36f9065dcacbd5c0ae2506037afe926f24f8042
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF contains embedded JavaScript, which is a common technique for delivering malicious content. The heuristics indicate the PDF acts as a link farm, directing users to various compromised websites and disposable hosting, likely to download further malware. The ClamAV detection and ML classifier strongly suggest malicious intent, consistent with phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://medvor.ru/uplcv?utm_term=probability+and+statistics+for+engineers+and+scientists+8th+pdf PDF link annotation
    • https://arendic.cl/files/34682730523.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608b77c32160f---60855777170.pdfIn PDF document text
    • http://evohome.pl/userfiles/file/wavuferojo.pdfIn PDF document text
    • https://sanxuattrucauthangkinh.com/Images_upload/files/49641159915.pdfIn PDF document text
    • https://erinmillssmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/1p9dqldaemqb7k5vrgou117eq1/43930652682.pdfIn PDF document text
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/697672772d91ba67b96901bab574d52b/22296934382.pdfIn PDF document text
    • https://alignerco.com/wp-content/plugins/super-forms/uploads/php/files/58e924c410ed96dab105559811f7a9bd/figuj.pdfIn PDF document text
    • https://marksiegeldds.com/wp-content/plugins/super-forms/uploads/php/files/95248bd20279b8eec7c6346013bf66fa/79453529955.pdfIn PDF document text
    • http://studiotecnicofrisoli.com/userfiles/files/36619263936.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/160766df0d6476---26298526410.pdfIn PDF document text
    • http://jayeonrak.com/upfile_editor/2021/files/kidixogimixike.pdfIn PDF document text
    • http://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b7e4ce9c9bb---85022552790.pdfIn PDF document text
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b958cc4324d---86992228429.pdfIn PDF document text
    • http://springswellness.net/wp-content/plugins/formcraft/file-upload/server/content/files/160bcdf74bffc0---69889509365.pdfIn PDF document text
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607da52276cdf---lizuzelosamuxabejesix.pdfIn PDF document text
    • http://koreanhotpot.com/uploads/files/30480640749.pdfIn PDF document text
    • https://bistakalikotenetwork.com/userfiles/file/rasekedibetewuroseb.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/7169213429.pdfIn PDF document text
    • https://janeunchained.com/wp-content/plugins/super-forms/uploads/php/files/e5hl3btrst3j725nio3soj4fu7/jumotolexanus.pdfIn PDF document text
    • http://www.afurg.com.br/assets/ckfinder/userfiles/files/88540276752.pdfIn PDF document text
    • https://realwebguys.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099a29207830---99996928962.pdfIn PDF document text
    • http://adamlegal.com/userfiles/file/6698718431.pdfIn PDF document text
    • http://creptiles.dk/userfiles/file/29718468998.pdfIn PDF document text
    • http://docando.es/js/ckfinder/userfiles/files/12144469590.pdfIn PDF document text
    • https://pasarangroup1.com/contents//files/18456720021.pdfIn PDF document text
    • http://touristclub.in/userfiles/file/xogedug.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fa4283ea61---89105304889.pdfIn PDF document text
    • https://studio45.live/wp-content/plugins/super-forms/uploads/php/files/ufir2msqpdj1qgnm5r8g2u344m/18750847006.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_off0000dc25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC25 19104 bytes
SHA-256: c925b5c4835dbd63b72e81519f68da7792dd84dcd02f77b0d54fceec1e08a7ef
font_01_sfnt_off00010db9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DB9 11360 bytes
SHA-256: d6476bfb3b23497f405d33503506d905c1e0e2cd71be281b2404779a6efbcfce
font_02_sfnt_off00012808.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12808 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1