Malicious PDF — malware analysis report

Static analysis result for SHA-256 85fbd7342b678c6f…

MALICIOUS

PDF

116.2 KB Created: 2021-01-01 03:05:49 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-16
MD5: 31509e1a7c6571fdbfa9c37c5fe53798 SHA-1: 9e9cf087674d76a498815140a8ac6cd4a35a59ff SHA-256: 85fbd7342b678c6f7d8a13e90df5baefbc145c0ecc82d0bef9512f69c46725b1
186 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO manipulation tactic. ClamAV detected this file as 'Pdf.Phishing.Trojan', and the ML classifier also flagged it as malicious. The embedded URLs suggest a phishing or malware distribution attempt, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://traffset.ru/123?utm_term=russian+alphabet+cursive+pdf PDF link annotation
    • https://zozesikijep.weebly.com/uploads/1/3/4/5/134586683/8597815.pdfIn PDF document text
    • https://bepusubo.weebly.com/uploads/1/3/0/8/130814017/topewemulu_jetolokox.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4427104/normal_5fb8644038cc9.pdfIn PDF document text
    • https://reninifovebomul.weebly.com/uploads/1/3/4/3/134361606/rarut.pdfIn PDF document text
    • https://cdn.sqhk.co/tavikagisato/h8pDdge/bipasokozutasizulepegaju.pdfIn PDF document text
    • https://cdn.sqhk.co/lulaxujik/jainaha/87674489686.pdfIn PDF document text
    • https://cdn.sqhk.co/banifiga/Njfnqhf/33759022788.pdfIn PDF document text
    • https://mujolimu.weebly.com/uploads/1/3/4/8/134868529/tuzas.pdfIn PDF document text
    • https://pesajupamobe.weebly.com/uploads/1/3/1/6/131607203/masijawaf.pdfIn PDF document text
    • https://cdn.sqhk.co/jogepirar/cAjhtKP/weekly_chore_list_printable.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385617/normal_5f90847a566ad.pdfIn PDF document text
    • https://cdn.sqhk.co/mozedizupi/6lRPEhh/bezapif.pdfIn PDF document text
    • https://cdn.sqhk.co/lisutovudaf/Khhgwjb/my_connect_kingston.pdfIn PDF document text
    • https://cdn.sqhk.co/moviferu/UiMGij6/skype_vs_hangouts_2020.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/bugutaj/nofovogirunesoxepenififez.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/ca323194-594f-4ea8-b1af-ebc3b1553a7b/22257561406.pdfIn PDF document text
    • https://s3.amazonaws.com/betefowubevat/endocrine_system_disorders_lab_answer_key.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8f8d344d-4fa9-4101-83b7-4a429898268b/fundamentos_da_fotografia_digital.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://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00019c08.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x19C08 22204 bytes
SHA-256: 3a7fae96a20af0e30f31bae2592c1fdcc528e028a902d837fab3b9c4ee7bfcd1
font_00_sfnt_off00013b29.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13B29 5448 bytes
SHA-256: 8e3b7a8867f0db874cbc753ef40354f85378b0c24752be6e911162d6ff29b6d8
font_01_sfnt_off00014db1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14DB1 27756 bytes
SHA-256: 7e3ca9fbf8a2db1ce89a9e3f35b0bef3f441a5c723341287a96ece1469c3af60

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