Malicious PDF — malware analysis report

Static analysis result for SHA-256 36e90582773f0610…

MALICIOUS

PDF

77.9 KB Created: 2021-09-12 04:04:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: ce52e50fa74722e31a681b48772c1c20 SHA-1: cbca5452034b874dde1d6e1c4c48becabf84643d SHA-256: 36e90582773f0610c08420355dd82a2ceda3b98f13fc251f260cd0d1845b41e1
126 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated a high probability of maliciousness. The document contains a large number of embedded URLs, many pointing to disposable domains, suggesting a link farm designed to redirect users to malicious content or download further payloads. While no scripts were explicitly extracted, the nature of the embedded URLs and the PDF structure strongly suggest an attempt to exploit users through malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

Heuristics 5

  • 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 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://siangyun.com/upfiles/editor/files/mofujuw.pdf In PDF document text
    • http://peterpan1996.it/userfiles/files/41506866990.pdfIn PDF document text
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613bdbf394e17---56736037301.pdfIn PDF document text
    • https://nezrenweb.com/calisma2/files/uploads/mununugukulaxosidopejusuj.pdfIn PDF document text
    • https://maidintown.co.uk/wp-content/plugins/super-forms/uploads/php/files/7998f43d5c3e1f07b03ab680253ea356/numesamopodurekimesibijig.pdfIn PDF document text
    • http://les-dvorik.ru/userfiles/file/38778648194.pdfIn PDF document text
    • https://himalmanpower.com/ckfinder/userfiles/files/lisiluwutozeli.pdfIn PDF document text
    • https://divetechmarine.com/contents/files/vilulikexelidu.pdfIn PDF document text
    • http://yesfabric.com/images/upload/File/vamuv.pdfIn PDF document text
    • http://precedent.by/_newsite/images_from_html_editor/file/1792376832.pdfIn PDF document text
    • http://pegasomeeting.medcoast.net/ckfinder/userfiles/files/lixoxibutezomiwemitapi.pdfIn PDF document text
    • http://ducnhua.com/upload/files/79063891247.pdfIn PDF document text
    • https://path.mn/userfiles/files/zeraxopusaduvatabonu.pdfIn PDF document text
    • http://minipit.com/data/files/13822850506.pdfIn PDF document text
    • http://rovitek.com/userfiles/file/sezosotuseri.pdfIn PDF document text
    • http://nhasachthunam.com/upload/files/gilusovufunudeduworul.pdfIn PDF document text
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/37542280877.pdfIn PDF document text
    • http://www.vljainandco.com/userfiles/files/8404411083.pdfIn PDF document text
    • http://bestapp4u.com/admin/uploadedfiles/file/dirutixulesuvidujezat.pdfIn PDF document text
    • https://viettrungson.com/media/Files/62454361893.pdfIn PDF document text
    • http://fertilityupdates.com/userfiles/files/kizofunuxuzarisanamibe.pdfIn PDF document text
    • http://mobilenmr.com/files/files/mixugovepinero.pdfIn PDF document text
    • http://tvsatkrosno.pl/userfiles/file/natemir.pdfIn PDF document text
    • http://minhnguyenvn.com/uploads/userfiles/file/xodoz.pdfIn PDF document text
    • http://tantusmarina.com/UserFiles/file/jarevomufufadokijigomori.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/cv9VXjIrmdE/uplcv?utm_term=android+developer+homePDF link annotation
    • 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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c846.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC846 10276 bytes
SHA-256: 480461c0c672c8a5c25edb945ef07b8ebb657487e0302d211370ffde1ba50fe1
font_01_sfnt_off0000df13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF13 19364 bytes
SHA-256: 381a9d04f04b62fcea22b5890d92fd18eb92ceca013a430d0b0a53e07325bc91
font_02_sfnt_off000111c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111C6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1