Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c5b95743a11e2c6…

MALICIOUS

PDF

82.9 KB Created: 2021-09-11 10:23:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 03f2ad978d185c2a6c8dc83c5e4c3cbc SHA-1: f02b64b232a834b4bdb1197fecde5fc9e228ff89 SHA-256: 6c5b95743a11e2c6dd1294f50e7df1be89010a84d4113f0e381e01adfb1a54aa
96 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to external PDF files hosted on various domains. Several heuristics indicate this is a link farm, with some URLs hosted on compromised CMS upload storage. The ML classifier strongly suggests malicious intent, likely to lure users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://somogyplusz.hu/files/40110240845.pdf In PDF document text
    • http://freeware-software-download.de/uploads/editor/file/60689642093.pdfIn PDF document text
    • http://faurerom.com/userfiles/file/14978846727.pdfIn PDF document text
    • https://www.comperat-89.fr/ckfinder/userfiles/files/18618664300.pdfIn PDF document text
    • https://orig-shop-gsm.ro/ckfinder/userfiles/files/35950397880.pdfIn PDF document text
    • http://ambiance-cinema.fr/wp-content/plugins/super-forms/uploads/php/files/08dfd9d74644bd05b7a7d88e42d785ef/53717697139.pdfIn PDF document text
    • http://eptesteplelek.com/uploads/file/buxuki.pdfIn PDF document text
    • https://free-spirit-city.eu/uploads/wysiwyg/files/gidejigigewobimez.pdfIn PDF document text
    • https://oneremote.ru/wp-content/plugins/super-forms/uploads/php/files/bf2763bab9bb9be05b0e182e27fdc776/taraxoboj.pdfIn PDF document text
    • https://happycustomerservice.com/wp-content/plugins/super-forms/uploads/php/files/e6121bd0e5372596243790fd971e5cdb/xisifipif.pdfIn PDF document text
    • https://gotoko.com/cmsv2/upload/files/fibutaxip.pdfIn PDF document text
    • http://mextro.de/upload/files/73976374928.pdfIn PDF document text
    • http://smwiarus.pl/ckfinder/userfiles/files/9534524907.pdfIn PDF document text
    • http://abwjefferson.com/uploads/files/bijatijarer.pdfIn PDF document text
    • http://foodzipo.com/uploads/userfiles/files/59494140450.pdfIn PDF document text
    • http://zlzljc.com/uploadfile/file///2021091113133179.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613a7a891bd0a---31387662696.pdfIn PDF document text
    • http://xn----7sbbgprpk7biiq.xn--p1ai/admin/ckfinder/userfiles/files/raxenil.pdfIn PDF document text
    • http://www.magicapro.it/wp-content/plugins/formcraft/file-upload/server/content/files/16134e68b7931f---ketebi.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613553c8743a1---purakapusasakek.pdfIn PDF document text
    • https://crbz.ru/userfiles/file/tewedoxusegujet.pdfIn PDF document text
    • http://hyundaidongdo3s.com/images/files/dufomajukedo.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613916c260525---73998468366.pdfIn PDF document text
    • http://zaiger.ru/img/file/14431120509.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=unlock+phone+after+factory+resetPDF 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_off0000de58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE58 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f66f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF66F 10696 bytes
SHA-256: 016efd1d1de732cdb379c0145c3653d4fa8d191a9cb6b7cfea30b0fd0446e0e0
font_02_sfnt_off00010efa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10EFA 18296 bytes
SHA-256: 62119a9c08eb11fa4b8a1c6d77e7ae865277026f3bbbfd749a596a00ddf7c895