Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9f018b4bee7dc3f…

MALICIOUS

PDF

91.7 KB Created: 2021-04-04 16:14:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-27
MD5: 9448871177a132981b66e7fe7f83a4f2 SHA-1: 41522a67092f9096d37706015afd87e376241f53 SHA-256: b9f018b4bee7dc3f649e4673ec77f81baf6ff59eb09f8b50905477516e2f1956
194 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable domains, suggesting a link farm or SEO spam operation. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware distribution via these links. No scripts were extracted, but the PDF structure itself is used to host and distribute these malicious URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://soxebez.ru/award?keyword=biochemistry+course+syllabus+pdf PDF link annotation
    • http://nasporte1.fun/pokemon_pixel_character_creatoroibdg.pdfIn PDF document text
    • http://zhenskiizhurnal.ru/how_to_pick_an_ar_15_upper_receiver5sect.pdfIn PDF document text
    • http://esclick.pro/3294317008ygemg.pdfIn PDF document text
    • http://goodsfor.life/princpios_de_qumica_atkins8clxr.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/471d79a4-a187-4cc5-81c9-7410de663a21/26950036856.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ee04207c-f7a9-4857-9eab-9c1a3dc04ded/what_is_the_meaning_interest_rate_risk.pdfIn PDF document text
    • https://f8340159-69ce-4309-ac43-521e9a8475b4.filesusr.com/ugd/bc0b97_7136c03052474e00bb0a2053178ea24e.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/buwosevax/tenancy_agreement_template_word_document.pdfIn PDF document text
    • https://c7bff75e-0a19-4817-9d47-fca4cf08161b.filesusr.com/ugd/3b6424_dc86e6be2707487cadef57fe7c5451a2.pdf?index=trueIn PDF document text
    • https://69df74eb-9f83-488d-97bb-abb55063df61.filesusr.com/ugd/f34323_258b746365e94d4382e98166a4dbccc0.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/vudivuzakal/tomubexupaponubuferiba.pdfIn PDF document text
    • https://c8070bf9-ed42-4c5d-8eb8-ca35ee70f136.filesusr.com/ugd/d38238_7605ef35c12d4992a6fe78f86c99ca48.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9da83c53-7dcd-4df4-90fe-4273232781e6/40105703626.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/73d0866d-2834-492e-9883-faf37a8b5ad7/maytag_centennial_dryer_switch.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1057a73c-d6b4-4f9f-81a4-d3c6721fe141/g_shock_ga_110rg_1a.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/10db6703-f18b-408c-b62f-fdd12dcd2c5b/jeep_wrangler_body_repair_panels.pdfIn PDF document text
    • https://7e079b21-6cfc-4bbc-a8af-001f4930a7f2.filesusr.com/ugd/f66805_0a61020a982d4ee392c3502d33090053.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/gifojuxaxeva/odd_even_functions_worksheet.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9f3a831b-94ef-4888-bcf9-acbdd0bb35cf/how_to_clean_filter_on_rinnai_gas_heater.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001198d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1198D 5464 bytes
SHA-256: 97bdbd18b01e73fb4c9a541af6597157170fe3a064fb94ef762db041add34de9
font_01_sfnt_off00012c17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C17 11608 bytes
SHA-256: c47b48069456462ffe2dd10c40f27e72538b0b3da6697a61c20fba7fbea091af
font_02_sfnt_off00015378.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15378 4324 bytes
SHA-256: cd94ef65598b1866d0653cdd88243d989fd81359c0e770c2d3a4858f1c2f6d34