Malicious PDF — malware analysis report

Static analysis result for SHA-256 81c64ed95c811e93…

MALICIOUS

PDF

86.9 KB Created: 2021-04-10 01:49:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-13
MD5: 0492d3a8c5c67327ba01c12a17b0d18d SHA-1: 0058a20ab6f027b084579f01ffcae686654f5418 SHA-256: 81c64ed95c811e939f0ea6b14b459afe5acc6fcb73021be3f6c35b9548602f69
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF document was identified as malicious by multiple heuristics and an ML classifier, including critical alerts for linking to known malicious redirectors and hosting a link farm. The embedded URLs suggest an attempt to lure users to external sites, likely for phishing or to download further malicious content. The document's structure and content indicate it is part of a link farm designed to generate traffic or distribute malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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 links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • 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.
  • 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://dafemum.ru/strik?utm_term=is+a+muppet+christmas+carol+on+tv+this+year+2019 In PDF document text
    • https://cdn-cms.f-static.net/uploads/4478132/normal_6031752da407e.pdfIn PDF document text
    • https://cdn.sqhk.co/ligilitojob/cia2rsI/mufavixajewadivekoge.pdfIn PDF document text
    • https://cdn.sqhk.co/temegolu/Pw3Xmhc/funorakatoju.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4370056/normal_5fdd84916f382.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4420907/normal_5ffa1f338f5a9.pdfIn PDF document text
    • https://cdn.sqhk.co/tezejikibus/gh7gcUW/40279843904.pdfIn PDF document text
    • https://cdn.sqhk.co/rafujajek/b3CJwgj/flapdoodles_ice_cream_menu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/9bd95890-f4f0-4baf-8ecd-cada02ef3d33/honeywell_thermostat_th8321u1006_replacement.pdfIn PDF document text
    • https://s3.amazonaws.com/sepawi/esl_grammar_worksheets_free.pdfIn PDF document text
    • https://s3.amazonaws.com/sagotomagin/spotify_mod_apk_songs.pdfIn PDF document text
    • https://37991ae0-d72b-4ccf-bf90-288dedd591e7.filesusr.com/ugd/041b56_0f692b3e993e4a5dad03841be21e72da.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/28c1ad36-51f2-47ab-9a75-f2b8e30a5976/92528025675.pdfIn PDF document text
    • https://081e7fb2-604d-424b-9b75-a58d54a71a44.filesusr.com/ugd/abd6ea_0cfe614e8f09406c9ab4937d6ce23253.pdf?index=trueIn PDF document text
    • https://9df6fdd8-df71-43fb-87ad-b121b2de7416.filesusr.com/ugd/e0d0cf_d2b6169902d64defab74e44d2d64c45f.pdf?index=trueIn PDF document text
    • https://a943cdc4-551e-4fd6-8842-bb1c82e441e2.filesusr.com/ugd/a0303e_cf5ae90da7644af495d8ccccb62f5d5f.pdf?index=trueIn PDF document text
    • https://3ff4c494-4984-418a-b709-7a5c611cca0a.filesusr.com/ugd/adbee0_7a7078a2fb70408c8f5b3a510a70e291.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/jaxesabi/capital_campaign_plan_template.pdfIn PDF document text
    • https://67258aaf-84c5-4a88-bfd2-1aa7ddb6c27a.filesusr.com/ugd/850f07_13dbb8500b1e4151b55cfe5772ebff09.pdf?index=trueIn 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_off000114c9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x114C9 5756 bytes
SHA-256: fefae908e86a25e55673d8b2690874525a0a40c63a3eb42293128a4efa129dfc
font_01_sfnt_off0001283f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1283F 11096 bytes
SHA-256: 614a6875a0103a57e7ebe07df4387f2ae5f6838b7d5a677e6ad7a67cd634a053