Malicious PDF — malware analysis report

Static analysis result for SHA-256 32d21b16547deea8…

MALICIOUS

PDF

68.2 KB Created: 2021-06-07 01:28:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0435e7b7ffa85f0163ffdbe49c213e2a SHA-1: dcdf0df893e185f853c6572d3b92812fedb9ecb4 SHA-256: 32d21b16547deea8e94d5edb13f539c7f8540dae5852fe62f595ce3e675daf04
164 Risk Score

Malware Insights

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

This PDF sample was flagged by multiple heuristics, including a critical ClamAV detection and an ML classifier, indicating malicious intent. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics, along with numerous extracted URLs pointing to compromised or disposable hosting, suggests the document is part of a link farm designed to redirect users to malicious content. The SE_INVOICE_LURE heuristic further supports the phishing pretext, likely aiming to trick users into clicking these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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://synerhu.ru/uplcv?utm_term=flowchart+questions+and+answers+pdf
    • https://www.ferienhof-schneider.de/wp-content/plugins/formcraft/file-upload/server/content/files/1609df4c2199fa---45480221816.pdf
    • http://grawerlik.pl/userfiles/file/sinefubovamezebolisi.pdf
    • https://samarpanbharat.org/trila/userfiles/file/92488742600.pdf
    • https://www.indee-r.fr/wp-content/plugins/super-forms/uploads/php/files/9a2ccf1cdae5754812be9d983d723cde/gixaxaz.pdf
    • https://diversifiedhumansolutions.com/wp-content/plugins/super-forms/uploads/php/files/28885ca3a70a3c4a28638f0407d31d36/83077400842.pdf
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc6c653cd8---26436530691.pdf
    • https://journeypeople.cc/wp-content/plugins/super-forms/uploads/php/files/17df10138dbcc0635c336984e6b06d94/93250788769.pdf
    • http://matsonconstruction.net/userfiles/file/barojuzedepapaneg.pdf
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d184b9a1b7---tefajefafibalevimudek.pdf
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609db5ac8fa88---sadugo.pdf
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b209c37532d---71274637379.pdf
    • https://ladychief.com/wp-content/plugins/super-forms/uploads/php/files/db916363e5256de024d9ff028d6c93f8/witugatuxekeg.pdf
    • http://tnslib.net/userfiles/files/nalobamusudafojerimul.pdf
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16086c8d7e5498---78393080285.pdf
    • https://goldenparadisestsimons.com/wp-content/plugins/super-forms/uploads/php/files/869ce53a896df943bd1f9c68be08f2bb/tadivowif.pdf
    • http://aleeblog.com/wp-content/plugins/super-forms/uploads/php/files/8doj1mte30lbbak35kjfpkeqr3/61859074041.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cd14.bin
5c4f9c908e3860780afdbf2f205e980ef18dc8ddc1c37daf4fbefd0b8e2fd21c
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD14 5416 bytes
font_01_sfnt_off0000df8d.bin
ab8673bc863867fd57db40e967cd645c7ff177a1ca1086d8e7185a87ffbc64ff
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF8D 10668 bytes