Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5b52d5d2942379c…

MALICIOUS

PDF

85.8 KB Created: 2021-05-13 15:25:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: 0efc3b545005393b80109477218ee49b SHA-1: 24fb410002b415001925f40e341369568c562c2d SHA-256: a5b52d5d2942379ce73a2063f6fc0f59c8ea6ed7902a87af763f16bf987448d6
126 Risk Score

Malware Insights

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

The PDF file is identified as malicious by ML classifiers and ClamAV, indicating it's a phishing or trojan attempt. It contains numerous embedded links, many pointing to disposable hosting, suggesting a link farm designed to obscure the ultimate destination. The document body, though heavily obfuscated, appears to be a lure related to 'electrical engineering books', likely to entice users to click on the malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://jottigo.ru/strik?utm_term=electrical+engineering+books+for+1st+year+pdf PDF link annotation
    • http://palawawez.mypressonline.com/47511774136.pdfIn PDF document text
    • https://cdn.sqhk.co/fifusaji/ifihugc/39008902326.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4454172/normal_603eb1a3b78cc.pdfIn PDF document text
    • http://worozoxiw.sportsontheweb.net/84114224069.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4446643/normal_5ff8db6c453bb.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4467581/normal_604d2c3b27597.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4366961/normal_5fcbff96d5e54.pdfIn PDF document text
    • https://cdn.sqhk.co/kinanekoxo/EjeWjdW/22538813936.pdfIn PDF document text
    • http://bixaxivajujojar.mypressonline.com/lujego.pdfIn PDF document text
    • https://cdn.sqhk.co/pikukafil/hegTugg/chess_online_2_player_link.pdfIn PDF document text
    • http://ziwewixowele.sportsontheweb.net/ceragon_ip20_manual.pdfIn PDF document text
    • http://zomolejefej.mywebcommunity.org/the_living_christ_printable.pdfIn PDF document text
    • http://zonagareme.getenjoyment.net/como_hacer_un_alambique_casero.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4393772/normal_605abfd3e12e6.pdfIn PDF document text
    • http://telozurilesojo.sportsontheweb.net/92788897705.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/ed6cf4e3-0345-4242-b908-4bf532eeae6d/lutavakomuxuwa.pdfIn PDF document text
    • https://5a060084-92f5-4e09-b02e-bbac8bb45871.filesusr.com/ugd/05c943_8515ce7f56b8485e95bc41c7604ceac5.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9471f1a2-dd1b-443e-8d9d-48bce04ff011/brother_hl-5250dn_printer_drum_error.pdfIn PDF document text
    • http://runuwug.myartsonline.com/42202084206.pdfIn PDF document text
    • https://94e55d9a-ad7c-4b6b-a54a-a00202ad3087.filesusr.com/ugd/208fd7_0411798a1a93486fb09d174b2d69e4e5.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/e5b58079-9757-4a72-9066-3ca08d7cccff/63160363665.pdfIn PDF document text
    • https://6184de0c-c318-42a7-882e-c5ddc63b817d.filesusr.com/ugd/1c8c1e_a6f27b6b4d8f47c0ad975b2a856ac2dc.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/b8b6263a-4a7f-443a-84b3-9191f4b6e8b2/ruud_tankless_water_heater_error_code_11.pdfIn PDF document text
    • https://dc383e6d-b7a3-4e67-a88a-227fa542b6c3.filesusr.com/ugd/72b0e7_f687ea5eb6314cb2a6fbace70e518cad.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_off00010e37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E37 5636 bytes
SHA-256: 716a42f9c522dc59577aa47a80df6943fa8630c25fbef2ec06b7bba0414839a3
font_01_sfnt_off00012181.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12181 11684 bytes
SHA-256: 53c311b88a5786dbcd28bce18b20dc8760510e011a42e6ad65879c13915e77a9