Malicious PDF — malware analysis report

Static analysis result for SHA-256 f1c888f820d64807…

MALICIOUS

PDF

87.2 KB Created: 2021-03-18 18:47:18 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-24
MD5: f03648d6a3e5e4dd353d92ccc50a3c25 SHA-1: 57eb00c2ed46b6b43c6adcc88bed2a4c608c147a SHA-256: f1c888f820d64807438c76b55cfaaf88192309f9ed025a5ca80d6851862942ab
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://lozipotod.ru/123?utm_term=bsa+public+health+merit+badge+worksheet PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4366011/normal_60509c261a170.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4478683/normal_600283741fb6c.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4451766/normal_5feef959cee90.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4457311/normal_5fdaad9be036c.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://f8340159-69ce-4309-ac43-521e9a8475b4.filesusr.com/ugd/bc0b97_66d65b7ad0854745888c97fcc3701e0f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/347b34ce-1f3c-485c-9fa8-a5a82966d45f/what_is_the_main_point_of_hamlets_soliloquy.pdfIn PDF document text
    • https://s3.amazonaws.com/limewub/fluent_english_speaking_books_free.pdfIn PDF document text
    • https://s3.amazonaws.com/sojaxub/focusrite_scarlett_solo_connect_to_monitor.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/286d3cbb-778d-4e29-981c-86304beabe28/39073310250.pdfIn PDF document text
    • https://46a1ac71-481d-4a85-b709-d40f3a189542.filesusr.com/ugd/143c98_bb45c1da147f4559b5e72961bb1b6567.pdf?index=trueIn PDF document text
    • https://8717ace1-8174-44a1-9f98-e7cbf9e9ed94.filesusr.com/ugd/14e3be_3380b9c14d944083afc18bf197f93f61.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/mesixadelomomo/80211938868.pdfIn PDF document text
    • http://fupizasatekuw.rf.gd/exercises_past_simple_irregular_verbs.pdfIn PDF document text
    • https://s3.amazonaws.com/nagudo/30572982132.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3a8be0a7-215b-4fe0-b192-5ff3a770a4fc/372034013.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b373c352-f49a-4487-b014-8361bd99aca0/navien_ch_240_manual.pdfIn PDF document text
    • http://runugerobel.rf.gd/rented_property_inventory_template.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2c76bcb4-5901-458d-8ae7-aa4b91ae68e8/mumoridosudedamalepagugul.pdfIn PDF document text
    • https://da89e6ec-52f9-4c28-8de8-447a2e923c0c.filesusr.com/ugd/5e5b2a_7a6bee3d6e184f74bdc35815f9a48063.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010be6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BE6 5832 bytes
SHA-256: a0a4a7361cab88d621b7da7ccfd16b4ce0343b9f1d3e0397ee48ee9f4087827f
font_01_sfnt_off00011f91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F91 1800 bytes
SHA-256: 6d2a3a16cc464ce72cf05976c7f96a31c93af2202e0dc760c37a694345e222ee
font_02_sfnt_off00012821.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12821 10732 bytes
SHA-256: 339f7b19c2bb3f4423d0c1ac02fc42bad93235846ab2890f032b96a7f5e5792d