Malicious PDF — malware analysis report

Static analysis result for SHA-256 3b5c33b1811723f3…

MALICIOUS

PDF

82.2 KB Created: 2021-03-04 19:40:24 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-05-26
MD5: adb67e37814de4962b6df83e50df9668 SHA-1: e53fbbe7a9cf2a29346fab239f0183be53d17f0f SHA-256: 3b5c33b1811723f3dd95e61f2308ebea0f34d2c1ae17e34505d1ae576cb0e818
186 Risk Score

Malware Insights

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

The PDF contains a significant number of external links, many pointing to disposable domains, indicative of a link farm designed to redirect users to malicious sites. The ClamAV detection and ML classifier strongly suggest malicious intent, likely for phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and external link farm heuristic (PDF_SEO_LINK_FARM) point towards an attempt to exploit users through these links, aligning with spearphishing tactics.

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
  • 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://dugedepap.ru/strik?utm_term=the+lord+of+the+rings+all+cast+then+and+now PDF link annotation
    • http://uscreditmonitoring.info/42981468771wd3d2.pdfIn PDF document text
    • http://universal-kirov.ru/80300245543njvij.pdfIn PDF document text
    • http://fapseo.ru/best_kung_fury_quotes1oxja.pdfIn PDF document text
    • http://zememor.sportsontheweb.net/best_hunter_dps_build.pdfIn PDF document text
    • http://onesmall.space/how_to_write_a_paragraph_grades_3-56rewq.pdfIn PDF document text
    • http://sifimomikev.sportsontheweb.net/67126468239.pdfIn PDF document text
    • http://rozujed.sportsontheweb.net/skin_burning_sensation_on_lower_legs.pdfIn PDF document text
    • http://healthbeauty24.online/white_blank_imagex7fwp.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://44407f20-7244-4107-9544-84d8151b6f9a.filesusr.com/ugd/8508de_5aab4f0b4f384d98881a2d4a1b78971b.pdf?index=trueIn PDF document text
    • https://1fa67a36-2e8b-44cc-a955-751d80433762.filesusr.com/ugd/d85e51_f6f186859d844d8f9ec015d38b22c6b1.pdf?index=trueIn PDF document text
    • https://0c2a7d7b-be9d-4ef2-a94c-09ca905cc17d.filesusr.com/ugd/7d21c0_6c3ffbb98a234f759dd6b3e140708e42.pdf?index=trueIn PDF document text
    • https://d80868e2-5d34-4dda-9345-0396294a35aa.filesusr.com/ugd/f9fac6_4329a2e8c30a4720a6e02aba3f4852f0.pdf?index=trueIn PDF document text
    • https://bb55feb6-a0c4-48ae-8f72-aea2c45912f8.filesusr.com/ugd/b9801a_855fc5e07c9243809bda259d8d99b6b4.pdf?index=trueIn PDF document text
    • https://6478d21b-237c-41b5-add8-96d7b9819624.filesusr.com/ugd/c7ef1a_551f0454e6074b97b153f1cd3fad1e4d.pdf?index=trueIn PDF document text
    • https://7915398d-c9c2-4241-abdb-40cf742e4b8d.filesusr.com/ugd/d4df0f_f08ca24f442b43d8b9fecb0270d1670e.pdf?index=trueIn PDF document text
    • https://a1c9bafd-2917-4c1b-b79c-a4b44a941470.filesusr.com/ugd/f0f215_fa423a1e750d4d2dbdf571ce564a5543.pdf?index=trueIn PDF document text
    • https://4121a797-204a-431c-92a8-8e24072fb342.filesusr.com/ugd/b972d5_5740313bbd494727b02a8c493435dd27.pdf?index=trueIn PDF document text
    • http://diwavubodinaroj.myartsonline.com/dewalt_d55146_type_8_parts.pdfIn PDF document text
    • https://8319d365-0190-44ee-b2f3-e76f6fd230eb.filesusr.com/ugd/112488_d1e4636eabad42cf895faa25d44a4fa9.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_off000104e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x104E7 5324 bytes
SHA-256: 5031d65da01ed636f2ac3aa3e168d177af25e6f6ca977a605d8ad8645ad27f56
font_01_sfnt_off00011712.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11712 10688 bytes
SHA-256: f5658dfd3d312eddaa28233ba3a2b25b0777e6fc968ef264a3a70f6b7796ea5d