Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8dd455233a063e2…

MALICIOUS

PDF

75.9 KB Created: 2021-04-01 10:08:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: babdab795d9ffe4d1ba35f17ece0ec10 SHA-1: ada662b12c51b07c5cebcd9eb31bcbc6a84fd7a4 SHA-256: a8dd455233a063e2819ee84961d95d716f83721bf7e2f1729e4f9dfd65edd7f6
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript T1203 Exploitation for Client Execution

The PDF document contains a mass of external links, many hosted on disposable domains, suggesting a link farm designed to distribute malware or conduct phishing. ClamAV detected this file as Pdf.Phishing.Trojan, and ML classification yielded a high probability of maliciousness. The document body, though heavily obfuscated, appears to be a lure related to educational content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

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://lozipotod.ru/123?utm_term=index+notation+gcse+worksheet PDF link annotation
    • http://mavaxur.mywebcommunity.org/jack_and_the_beanstalk_movies_from_1990s.pdfIn PDF document text
    • http://kigurumi.org/bloomberg_new_energy_outlook15qae.pdfIn PDF document text
    • http://liko-sneakers.com/psychology_101_quiz_answersp22ii.pdfIn PDF document text
    • https://cdn.sqhk.co/letarezetap/6hdigjb/calligraphy_fonts_free_marathi.pdfIn PDF document text
    • https://cdn.sqhk.co/kivipemo/CsqibHb/duzibadufefubonatamarukez.pdfIn PDF document text
    • http://copyrightproblem.com/interview_questions_and_answers_for_case_manager_positionlimmu.pdfIn PDF document text
    • https://cdn.sqhk.co/reditifotep/ijcMuge/bezinujemoza.pdfIn PDF document text
    • http://expressday.online/surprising_things_that_have_gluten_in_themo0fye.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://16e729f2-8c5c-4787-b670-14aeba6c5e03.filesusr.com/ugd/ac55e2_a2186b21cdc848079ad9ebfbe6d210f3.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/697d75ab-a21c-43ac-9418-bf19eb164830/63196773197.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ef745b11-1627-46cf-abab-d6230390e754/zodoxibabedizifubejuluza.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/4a0f005c-6810-416d-a997-83ddfa89fc3e/how_much_is_mark_vincent_worth.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/61a19b87-c613-4f9c-a82d-0e1e8fc7952d/britax_marathon_expiration_date_2014.pdfIn PDF document text
    • https://bf6af823-cb0d-4ee8-9d5b-4f0b1de5ed24.filesusr.com/ugd/9eb187_d5060640d8694ba5bc638e0645bf19d5.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/2b28d9ff-6195-402a-a5cc-d2d02240a797/2001_subaru_outback_oil_type.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/30c40333-cef2-4e0e-98ca-1ca8afb383e2/nolukisewuxezusejojo.pdfIn PDF document text
    • https://254b3b0b-79dc-4992-827c-fd4bb3db3178.filesusr.com/ugd/f515ca_2661884fa2f445c492141848a2ae02f6.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/b54fdda4-6610-4b29-860e-82140eaec57d/dell_vostro_1500_maximum_memory_upgrade.pdfIn PDF document text
    • https://36fc1fe3-b646-4cc1-b6e9-de51469aea27.filesusr.com/ugd/3eb4bd_75c5492e165e40ccbc647b3b7c694e5a.pdf?index=trueIn PDF document text
    • http://xisuwujilaxemer.myartsonline.com/40768949252.pdfIn PDF document text
    • http://gefilodeza.myartsonline.com/debanikaguba.pdfIn PDF document text
    • https://6184de0c-c318-42a7-882e-c5ddc63b817d.filesusr.com/ugd/1c8c1e_1ba36e436a04414fa5a61316362a189a.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_off0000e8a5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8A5 5332 bytes
SHA-256: 23a73689000cfd11dbe870de319ee96fafe48a926f495c5a4c6218a165924f6f
font_01_sfnt_off0000fad8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAD8 11572 bytes
SHA-256: 20ae2d5334e86dbd1bd3ffdcfbb3ab4958ddfa591b452a8e8aba827860669f1e