Malicious PDF — malware analysis report

Static analysis result for SHA-256 da8381d25ba8ddbb…

MALICIOUS

PDF

74.1 KB Created: 2021-04-19 09:14:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 6afc5982cc073a45a90a7629a5ea7485 SHA-1: 78df14b5a328263623437fa4da350977c664395d SHA-256: da8381d25ba8ddbb267a41ee20c1b9d5aabb65b4b07d8b296a4f4f791ab2a2ce
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or phishing attempt. The ML classifier and ClamAV detection strongly suggest malicious intent. The presence of embedded URLs and the overall structure point towards a spearphishing attachment designed to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9999

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
  • 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.
  • 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://nipisod.ru/strik?utm_term=new+divergent+book+2020 PDF link annotation
    • http://lovewaits.ru/66737925854ubux.pdfIn PDF document text
    • http://lnstagram-helping.live/what_is_the_best_real_estate_brokerage_firm_for_beginnerspo5mu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369310/normal_60645a1cca261.pdfIn PDF document text
    • https://bajomunimiru.weebly.com/uploads/1/3/1/0/131070213/vupejoxekisodejura.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4420454/normal_6055571020709.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477878/normal_601a16067ee42.pdfIn PDF document text
    • https://sizezowupoje.weebly.com/uploads/1/3/4/7/134704467/1253d5.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4410006/normal_5fd142c43abed.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/3a0f09dd-91b3-43e5-9c9a-0f33495fd04f/4876432745.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b152185a-6f14-4536-8b51-f7d2e2203f6f/46193525737.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/51afdf03-fed2-4a8c-86bd-faa8ed610937/root_word_phon_meaning_sound.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/fb73035c-0df8-43a0-b395-852a6d694e42/how_to_turn_on_yamay_fitness_tracker.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9c84565e-ecb5-4e3d-bde2-22b607e25811/chick-fil-a_cobb_salad_calories_without_dressing.pdfIn PDF document text
    • https://4a1cfc67-5981-466d-a13b-75576fe7431f.filesusr.com/ugd/64e449_3bf74973706541a5aedc5db2fb5a3f4f.pdf?index=trueIn PDF document text
    • https://0b7b936c-93ac-4a60-9644-6ba220b934cc.filesusr.com/ugd/b4bf80_a3d0cd0392a4410184c6f5d52330c5f5.pdf?index=trueIn PDF document text
    • https://7fd92c66-d3af-485c-b7a9-31529ddfb1b5.filesusr.com/ugd/997d0f_d5d6ed8b0b0b4655923ba99549459121.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/8fed7747-a726-4d2e-9703-031d64adc626/what_are_the_4_types_of_journalism.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_off0000e27e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE27E 5172 bytes
SHA-256: c96e6017e6117751912335e7999915c02ab2327f0f139d69bc29fb09dcbf35b9
font_01_sfnt_off0000f44e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF44E 11564 bytes
SHA-256: 984a3e16a259a0263d213eb40dc70f72740af38a76798edcf563e806f3449400