Malicious PDF — malware analysis report

Static analysis result for SHA-256 c671b35b323817f8…

MALICIOUS

PDF

73.9 KB Created: 2021-03-26 08:12:54 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-25
MD5: 78833a03074ef5ed474847bb57cf1892 SHA-1: baae967889628cd838962d2d7f387ce0ce004461 SHA-256: c671b35b323817f8d7abf71939f46c84f263c9330aa742c35e2df2dbc6a9c89a
192 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

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

The sample is a PDF file flagged as malicious by multiple heuristics, including a critical finding for linking to known malicious redirector infrastructure. The document body, though heavily obfuscated, contains text related to 'answer key' and 'wkhtmltopdf', suggesting a lure. The numerous embedded URLs pointing to disposable domains and link farms indicate a strong intent to redirect users to potentially harmful content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 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 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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/123?utm_term=dsssb+assistant+teacher+answer+key+2018 In PDF document text
    • http://sk-anker.ru/how_much_does_xfinity_security_costixcb3.pdfIn PDF document text
    • http://boomerangoo.site/bubble_shooter_level_gamecw9ic.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4484375/normal_601abb1cbc114.pdfIn PDF document text
    • http://zespodsvetkoy.site/21169202678gv5t.pdfIn PDF document text
    • http://raftgjgr.space/66567601690mk9dm.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4462727/normal_5ff84b714f801.pdfIn PDF document text
    • http://appeal-ig.com/woderaderusesm8b5.pdfIn PDF document text
    • http://akb54.ru/automotive_lighting_market_reportd08oq.pdfIn PDF document text
    • http://forexgeeks.net/50549798733kkpds.pdfIn PDF document text
    • https://cdn.sqhk.co/livukigelo/X0yghib/darisawebiregidujar.pdfIn PDF document text
    • https://cdn.sqhk.co/bubiwalifeda/5082Ohc/small_business_accounting_software_comparison.pdfIn PDF document text
    • https://cdn.sqhk.co/zowonefaso/gTggjdp/screen_recorder_android_11_pixel_2_xl.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4414174/normal_6050c7f865587.pdfIn PDF document text
    • http://dvigatel.guru/how_to_get_funding_for_a_nonprofit_startupnfnje.pdfIn PDF document text
    • https://cdn.sqhk.co/nivurerazusa/ibUiaid/22846807334.pdfIn PDF document text
    • http://reduslimitalia-oficial.site/22755846068svrqc.pdfIn PDF document text
    • http://acgmgroup.ru/makkar_ielts_writing_task_2_2020v7ob7.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://xasagode.myartsonline.com/nutodanivarubedatipitez.pdfIn PDF document text
    • http://sasaxunofob.atwebpages.com/how_to_program_remote_for_genie_intellicode.pdfIn PDF document text
    • http://lugivodunoxasi.atwebpages.com/modelo_de_base_de_datos_orientado_a_objetos.pdfIn 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_off0000e382.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE382 5772 bytes
SHA-256: baddfc12bd4373d4a20b26c372009fdbebac2e9be1062bdced86d4ba2fc72047
font_01_sfnt_off0000f741.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF741 10196 bytes
SHA-256: 2b4bb3a8dbcd03353a5f64a71730922097b9f3b6a613022011176649950cb2d7

Open this report in the interactive analyzer, or submit your own file for analysis.