Malicious PDF — malware analysis report

Static analysis result for SHA-256 bcb374cc25678740…

MALICIOUS

PDF

68.6 KB Created: 2021-09-17 17:25:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 18cf3d8682bb79d0b903f19f7f8b3a08 SHA-1: 5b2fafea18e27dae09e049b0594c4e7058dd5017 SHA-256: bcb374cc25678740645d64b2d5bc463ccf2fa94f31fb83cc11eee97c7deec49d
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as a malicious PDF by ClamAV and ML classifiers, indicating a high likelihood of malicious intent. The PDF contains numerous external URIs, many pointing to domains that appear to be part of a link farm, suggesting a phishing or malware distribution scheme. The presence of embedded URLs and the heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly support this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://krisoc.ru/uplcv?utm_term=all+free+skins+in+fortnite PDF link annotation
    • http://cicm2015.mist.ac.bd/app/webroot/ckfinder/userfiles/files/86895912865.pdfIn PDF document text
    • https://hsse.hssanesteban.cl/files/31714650762.pdfIn PDF document text
    • https://bosgo.mn/uploads/files/32166492301.pdfIn PDF document text
    • http://xn--d1achljw0b.xn--p1ai/content/upload/fataluselefas.pdfIn PDF document text
    • https://jhservice.net/imagenes/galeria/files/9202103866.pdfIn PDF document text
    • http://tubelessons.net/cms_images/file/4386174018.pdfIn PDF document text
    • https://habibitours.com/ckfinder/userfiles/files/motolawalugadereruki.pdfIn PDF document text
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f4430e9000---buronaxozefelopu.pdfIn PDF document text
    • http://lionsmarsala.it/userfiles/files/pukolom.pdfIn PDF document text
    • http://jj-metals.com/userfiles/file/2021090417490273499.pdfIn PDF document text
    • http://studiocariola.com/userfiles/files/jupavugogu.pdfIn PDF document text
    • http://olympusflights.com/files/files/vejusasedunag.pdfIn PDF document text
    • https://bikidi.com/UpFiles/WebEditorFiles/file/1662036262.pdfIn PDF document text
    • http://maslatalaia.com/userfiles/file/20252113440.pdfIn PDF document text
    • https://cmf8.ir/data/file/89492654038.pdfIn PDF document text
    • https://thaibamboorestaurant.ca/phpsites/bard_ford/uploads/file/woxegujujikulalokosu.pdfIn PDF document text
    • https://edgecs.com/documents/11121484256.pdfIn PDF document text
    • http://mygiftltd.com/userfiles/file/xagotewatofatuze.pdfIn PDF document text
    • https://loskutova.site/wp-content/plugins/super-forms/uploads/php/files/55492564bbaebc07c54e2330b990c834/bowulenamatabokes.pdfIn PDF document text
    • https://semagro-msw.ru/pics/images/file/sofawilelikozavirujupali.pdfIn PDF document text
    • https://umartravel.com/files/fotivaxovome.pdfIn PDF document text
    • https://lecachet.fr/docs/files/17946841970.pdfIn PDF document text
    • http://furnitura-syndicat.ru/ckeditor/ckfinder/core/connector/php/uploads/files/38439876903.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

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b098.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB098 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c8af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC8AF 10116 bytes
SHA-256: 5048a9c1a4cedf5a7cb9103fd2d8a657fd4bd91021e67f172ca3ca47ecf3fdac
font_02_sfnt_off0000df67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF67 15084 bytes
SHA-256: 8b19e857b553a7e0b3ca8c5d4be2887f7d075ac75e37bb5463597afc2c5c762b