Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4e8ca511e250936…

MALICIOUS

PDF

83.3 KB Created: 2021-06-05 18:05:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 62e8f8877222d0dea67f258029d8faf0 SHA-1: 20a58cfd51ed10e6555b96c243d00a14019e3231 SHA-256: b4e8ca511e250936d5e11d467a2ddcb9de357f62eecc06ee30bde15b039da5fe
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, with one identified as a link farm designed to obscure the final destination. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a deliberate attempt to hide the malicious URL, which is further supported by the 'ML_NYX_PDF_MALICIOUS' and 'CLAMAV_DETECTION' firings. The presence of an external URI pointing to 'botokaw.ru' suggests a phishing or malware distribution attempt, likely disguised as a driver download.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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 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://botokaw.ru/123?utm_term=acer+drivers+and+s+south+africa PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4375361/normal_60008245ea5a4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4382638/normal_606e210711d48.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4481420/normal_602ae15da614a.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379049/normal_5fd6394b7c39c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369514/normal_604cb6dc16c71.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/d52d213d-78f1-4613-a2f0-277a73f3eecb/can_am_outlander_650_service_intervals.pdfIn PDF document text
    • http://beratirupo.pbworks.com/f/what_sensory_imagery_means.pdfIn PDF document text
    • http://tekitejug.pbworks.com/w/file/fetch/144568293/14-6_practice_worksheet_probability_of_mutually_exclusive_and_inclusive_events.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e77d4027-5fc9-4d32-b313-f41f522acc50/bemolawovugow.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/853df409-71f1-4290-addf-cfb9b5fe87d6/85130227163.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dd3a4a93-b23b-4139-96c5-4607cc1d1a00/gexesa.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/d181ac77-fed4-4650-9251-a414559b3cd6/the_essential_chuang_tzu.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e662c283-2dc8-4d1a-bbfb-b1768a21d000/gujitijixemokupe.pdfIn PDF document text
    • http://pebolokunaz.pbworks.com/f/how_to_prepare_dextrose_powder_for_dogs.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/af003074-d756-4a0f-8280-04ad756bc119/bomivazadi.pdfIn PDF document text
    • http://kimotamiju.pbworks.com/f/is_shiru_wa_gp_a_soldier.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b84c89ec-8c6a-4c93-b058-42eb85d29174/nibevowitasurib.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/be40c06e-4334-4664-95c6-78e8f0d36b82/did_american_eagle_go_out_of_business.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/aec56008-278a-47ff-900d-a21884c2b5c9/cnn_current_events_articles.pdfIn PDF document text
    • http://tozuxexap.pbworks.com/w/file/fetch/144525450/leed_core_concepts_guide_3rd_edition_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/95a39637-52c9-4f95-a6a4-65f36f605108/kotijur.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_off000105b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105B3 5128 bytes
SHA-256: bcae66cd819140d9eb8e00f872cbe01dd54e68386130a5d7e0cfc6410ad8ed16
font_01_sfnt_off0001172b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1172B 11424 bytes
SHA-256: 36a448ac27ce3aa55a800a3a063c217b4867497528466fd1d535304e5af9f11e