Malicious PDF — malware analysis report

Static analysis result for SHA-256 3729be40cf8cd85c…

MALICIOUS

PDF

75.3 KB Created: 2021-04-03 02:08:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 321af41b52ed568bf3b58cef6f7875e7 SHA-1: 14643b0a0aae6a1fa165d2762ba658830dfc0f1b SHA-256: 3729be40cf8cd85cc06d1d8771dfc3660c4294a2898b9fc0ab1eebce5c5f9800
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, suggesting a link farm used for SEO manipulation or to distribute malicious content. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware delivery. While no scripts were explicitly extracted, the PDF structure and link farm heuristics point towards an attempt to redirect users to potentially harmful sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • 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 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://zajinet.ru/award?keyword=cds+syllabus+pdf+2020 PDF link annotation
    • https://dixozetazexode.weebly.com/uploads/1/3/4/4/134472526/wujunonidatata.pdfIn PDF document text
    • http://fovikoxesaweziz.medianewsonline.com/29208733323.pdfIn PDF document text
    • https://finiluxib.weebly.com/uploads/1/3/5/3/135350298/kiwufewaxexekil.pdfIn PDF document text
    • https://kakerenu.weebly.com/uploads/1/3/1/0/131071145/dinepepo.pdfIn PDF document text
    • https://pasuwuzo.weebly.com/uploads/1/3/1/4/131438486/zimogiso-mojegagar.pdfIn PDF document text
    • http://zukirudon.mypressonline.com/the_stranger_camus_book.pdfIn PDF document text
    • http://nusowutevu.getenjoyment.net/48366927745.pdfIn PDF document text
    • https://tekopazaxalar.weebly.com/uploads/1/3/4/3/134348639/4445363.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://vofiwevo.epizy.com/xmanager_free_for_linux.pdfIn PDF document text
    • https://s3.amazonaws.com/xufoxorog/free_bookkeeping_software_for_small_business.pdfIn PDF document text
    • https://s3.amazonaws.com/rumezo/their_eyes_were_watching_god_chapter_13-16_summary.pdfIn PDF document text
    • http://nanizezuzodujo.epizy.com/dixie_chopper_xcaliber_4x4_price.pdfIn PDF document text
    • https://s3.amazonaws.com/gozilum/lujulu.pdfIn PDF document text
    • https://3c3a732a-bc26-4be5-bc29-345d3dbc3408.filesusr.com/ugd/63a963_a65094109cb24ab58b9879db7105bba6.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/5d6d31c1-4dbc-45c4-a279-fb3673ae1884/xuruguzebamuzujusimamizaj.pdfIn PDF document text
    • http://laxufazekez.atwebpages.com/una_canzone_d_amore_testo.pdfIn PDF document text
    • https://6fd4412c-3e6e-4f21-a9af-8137ffc6c0d9.filesusr.com/ugd/03469c_7f41030e42a24a88ad843b35c3ddb137.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/fec34215-f8f2-4e71-81e9-fe711fe6b150/quotes_from_the_selection_series_with_page_numbers.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/03c4c026-3664-44dd-9b1e-2c83c87a98d2/wenavev.pdfIn PDF document text
    • https://77a5c3e7-429a-4f60-ad30-886abaef4f6e.filesusr.com/ugd/07a1ab_fa1185d803f0483fb0fdf67a307a6529.pdf?index=trueIn PDF document text
    • https://ad843f61-c544-48d7-8cfb-3c048b9edb46.filesusr.com/ugd/0dd9ed_a54acfdc326142d4b33582a96c6762c0.pdf?index=trueIn PDF document text
    • https://504b7f7c-d27d-4f2b-a6eb-e8dc7cf660cf.filesusr.com/ugd/6ba015_11288f876e9b4ec3bbed4a14b178a893.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_off0000e953.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE953 5360 bytes
SHA-256: c1717877ffe2caa25bf20564869b59013e94e3d127ca116d332f6ed8dc889ca2
font_01_sfnt_off0000fb9f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB9F 10744 bytes
SHA-256: 681c925fbf59e28d134abcbfbb79d7282557ddf1a9920861121921b17a87e089