Malicious PDF — malware analysis report

Static analysis result for SHA-256 f19f735906234633…

MALICIOUS

PDF

82.5 KB Created: 2021-03-28 02:59:25 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 76370d602ccc7d65c98c4661d7df71ac SHA-1: 240a079f3e2c540b8abcbf7d4d159a7aeeb21c41 SHA-256: f19f735906234633f598ad8fc39262e66e7a5aa038388f2e4ab46a2ad10f8aa7
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains a large number of external links pointing to other PDF documents hosted on various disposable domains, indicating a link farm or SEO manipulation tactic. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to distribute malware or engage in phishing. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, but the primary malicious activity observed is the extensive use of external URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://gimoguvi.ru/award?keyword=nomenclatura+de+alcoois+pdf PDF link annotation
    • https://ruritavi.weebly.com/uploads/1/3/3/9/133988031/4699630.pdfIn PDF document text
    • https://mologikonazo.weebly.com/uploads/1/3/4/7/134706863/3290910.pdfIn PDF document text
    • http://kavelokafozi.medianewsonline.com/zapubif.pdfIn PDF document text
    • http://xidufefonudug.sportsontheweb.net/puvejifakakivemux.pdfIn PDF document text
    • https://gozivuwedigati.weebly.com/uploads/1/3/4/6/134612943/5099823.pdfIn PDF document text
    • https://cdn.sqhk.co/divoxisig/EDbprjd/mawavef.pdfIn PDF document text
    • https://cdn.sqhk.co/kivipemo/igjogi7/nixotaxap.pdfIn PDF document text
    • https://cdn.sqhk.co/vozofugova/Qgheohc/sefodiveradepixojevazimax.pdfIn PDF document text
    • https://cdn.sqhk.co/wazilisiko/fiehbu7/tifolijalajenowujol.pdfIn PDF document text
    • https://cdn.sqhk.co/gadukupuwe/kuDOUge/50558812862.pdfIn PDF document text
    • https://ragitodis.weebly.com/uploads/1/3/4/7/134753297/d39359f7bf423.pdfIn PDF document text
    • https://cdn.sqhk.co/zivupowixede/6hjejfG/easy_repost_app.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4367911/normal_60176c1ea6d4b.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4379837/normal_5fde518146a35.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4494868/normal_5ff02ff802e8a.pdfIn PDF document text
    • https://cdn.sqhk.co/pijovowifil/yEhhe3G/roseref.pdfIn PDF document text
    • https://kipigifusulip.weebly.com/uploads/1/3/4/4/134437712/zofoliwiwunabudijuse.pdfIn PDF document text
    • http://domainlimax.xyz/molarity_practice_problems_worksheet_answersmqbjc.pdfIn PDF document text
    • https://cdn.sqhk.co/vemudumuxixu/aigjhhf/641272753.pdfIn PDF document text
    • http://getsol.xyz/as9100_rev_d_gap_analysis_templatebwxnx.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • http://sogivuwe.onlinewebshop.net/66761261071.pdfIn PDF document text
    • http://rogofideb.onlinewebshop.net/management_of_marasmus.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e8d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8D1 5152 bytes
SHA-256: aafecbf0c63faf315ed15d4d7bf6d76cf77c6fd63f062db8e176e61a8171b525
font_01_sfnt_off0000fa2c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA2C 2520 bytes
SHA-256: 26ac93315814f42a2399db89c53c757e72434be049311e25573298e7905510f0
font_02_sfnt_off00010483.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10483 13216 bytes
SHA-256: 035cb6736decdb36fc0991ca8b1d01ece394422d59b11a60a22b92d968f41ca2
font_03_sfnt_off00012ca1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12CA1 4324 bytes
SHA-256: a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f