Malicious PDF — malware analysis report

Static analysis result for SHA-256 c42356ca9ac428b8…

MALICIOUS

PDF

77.1 KB Created: 2021-06-11 18:07:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-23
MD5: 4f0e03a3a7de15ee4184664a552e93d4 SHA-1: 1247ef29f48f97edc5a5dfd773c5b6e2097469c0 SHA-256: c42356ca9ac428b84a97568662f75b9bc4946dc844b4ed91994640c1dbc6f3a9
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The sample is a PDF document flagged by ClamAV as Pdf.Phishing.Trojan. It contains numerous embedded URLs pointing to compromised websites and disposable hosting, suggesting a link farm designed to redirect users to malicious content. The ML classifier also strongly indicated maliciousness. While no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://coretry.ru/uplcv?utm_term=sidesteppers+mario+kart+tour PDF link annotation
    • https://prsnashville.com/wp-content/plugins/super-forms/uploads/php/files/1c1126bad3389f24d0218c5a7a99d422/88506267724.pdfIn PDF document text
    • https://www.ideaklinik.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f4bf3621f2---18213082122.pdfIn PDF document text
    • http://blpest.com/UserFiles/file/dojosizirubuzuximid.pdfIn PDF document text
    • https://foundryindia.org/userfiles/file/vegogonapif.pdfIn PDF document text
    • https://www.expoagrogto.com/wp-content/plugins/super-forms/uploads/php/files/3k4bjms7uscsm3au4kc7jjsih2/46356362735.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd5654e4ecd---1047066535.pdfIn PDF document text
    • http://juniorsmagazine.com/wp-content/plugins/formcraft/file-upload/server/content/files/160730eb5538b7---vuvoxuvuninoporijudifag.pdfIn PDF document text
    • http://alemotta.com/resources/original/file/86399274215.pdfIn PDF document text
    • https://chmelo.hu/sites/default/files/file/30307157166.pdfIn PDF document text
    • https://www.kiakaha.gr/wp-content/plugins/super-forms/uploads/php/files/lft2kn7pv94rvgggaje77vem5v/kurosidofo.pdfIn PDF document text
    • https://costumeworld.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071514428023---fefazumadawakuzom.pdfIn PDF document text
    • https://bindazzled.com.au/wp-content/plugins/super-forms/uploads/php/files/bb3b5214b84a0f29ed0ae8e6a1857445/69665722330.pdfIn PDF document text
    • https://newat.ru/wp-content/plugins/super-forms/uploads/php/files/3b892cd67891b0cdc6fa4f82286c14ae/95402917722.pdfIn PDF document text
    • https://oliogalanis.com/file/11677394245.pdfIn PDF document text
    • https://lapalettedesarts.fr/gestion/file/lobuvususuduliweso.pdfIn PDF document text
    • https://kakvkusno26.ru/wp-content/plugins/super-forms/uploads/php/files/8573eddcd014e7a2a5850617fd7d7c4d/wapozenubawebatunajo.pdfIn PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/8782bad0b8175fab8499c52a0c4e90df/86686849137.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f186.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF186 5240 bytes
SHA-256: 102369dac58feed4fcc6f4fbcbcb3a25b10b21ff0a968982e6e101cc6145a69d
font_01_sfnt_off00010340.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10340 10576 bytes
SHA-256: 00ee564fd1a028cbe00b89e658c81a6ddee53d2da86f8534a8885fadc6fd6b47