Malicious PDF — malware analysis report

Static analysis result for SHA-256 15b6d681f6cef2fd…

MALICIOUS

PDF

64.9 KB Created: 2021-04-29 21:56:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-14
MD5: a58d58838949285e7c868f6cfda97589 SHA-1: 898e5570491e635619ef6afdea19801e60ec71f4 SHA-256: 15b6d681f6cef2fd0cbf18e992297f13470085ae6153dc2726ba551f3bf96624
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with multiple URLs pointing to compromised WordPress sites. While no scripts were explicitly extracted, the nature of PDF link farms often involves JavaScript to facilitate redirects or exploit vulnerabilities, hence the inclusion of T1059.007.

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://vidolamerica.org/wp-content/plugins/super-forms/uploads/php/files/f5352eb69a3fe72cfd5ddca76f162690/pepakapa.pdf In PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/160822dbee9665---rilakitirimimexugonid.pdfIn PDF document text
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607c68512c218---vezelakipesu.pdfIn PDF document text
    • https://www.pietri-automobiles.com/wp-content/plugins/super-forms/uploads/php/files/3qna8np285tdd9cqq83qlnknc9/18261118408.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606d6171b9528---14048155027.pdfIn PDF document text
    • https://blackknowledge.com/wp-content/plugins/super-forms/uploads/php/files/373e71ed4100a77ee6557eb0bca92fe4/merasakutiw.pdfIn PDF document text
    • http://penoplex24.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16076a456ab665---35803451650.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607d0f0d37334---xefisa.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/3fb7d3485ab780fe79dba5eba209e0fa/noxamuxuselovufura.pdfIn PDF document text
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c655485023---bomegugoguboxiwen.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/ki6ko5ivd8vnpf4hb5pc0bklk3/guwifatogodevenetumux.pdfIn PDF document text
    • http://all-pass.com/folder/editor/file/25070143100.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/160776602d3aa2---28410432137.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/2db4345b445847e9dbcf97a9888ec3e2/85304408208.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=linearlayout+horizontal+scroll+androidPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c1f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC1F5 5120 bytes
SHA-256: a601833f57bc73fd42c2a930deba82bfb886168f508edd184b014bee1e2d0e3a
font_01_sfnt_off0000d366.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD366 10276 bytes
SHA-256: d7c66e2ec868bbce7194211091a8f5f5731a7ae0eb1b9e5a36c1234249eacdd6