Malicious PDF — malware analysis report

Static analysis result for SHA-256 9923f073afe5b176…

MALICIOUS

PDF

78.8 KB Created: 2021-09-12 16:43:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4b36dbae6de621a85e93f6c916007fc1 SHA-1: cdbe6ed8bb2749b69e2c5891e04841991585db54 SHA-256: 9923f073afe5b176aa687162c2bf2a61dfcf9c3eac193a98eb2a67f05ef34471
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to multiple compromised websites and disposable hosting, a common tactic for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is unreadable, but the heuristics and numerous extracted URLs confirm its purpose as a redirection mechanism.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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
  • 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 http://ceramvetro.net/userfiles/file/82806956204.pdf In PDF document text
    • http://cautrucpalang.vn/webroot/img/files/24604193566.pdfIn PDF document text
    • http://hftyby.com/upload_fck/file/2021-9-2/20210902231156741164.pdfIn PDF document text
    • http://hiroi-es.info/yamituki-n/uploads/files/mulutapinaregunelumepe.pdfIn PDF document text
    • https://rajaketiga.com/contents/files/taderomoka.pdfIn PDF document text
    • https://newshieldinsurance.com/demo/gsa/final/images/file/tugavevutakatad.pdfIn PDF document text
    • http://tdvvietnam.vn/webroot/img/files/39280120520.pdfIn PDF document text
    • https://tasteadmin.com/ckfinder/core/connector/php/custom/wysi_uploads/files/nivirugul.pdfIn PDF document text
    • http://kondicionery-himki.ru/upload_picture/file/72599006910.pdfIn PDF document text
    • http://ljsmelt.com/upload/files/63108429018.pdfIn PDF document text
    • https://hainutedecopii.eu/ckfinder/userfiles/files/xisujilozokipe.pdfIn PDF document text
    • https://barcelona-health.com/files/galeria/files/93159481131.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/c87eb231699eb0bbe86c349dbccf385e/85183364184.pdfIn PDF document text
    • http://videocycling.info/files/file/63868294301.pdfIn PDF document text
    • http://katyababash.com/images/uploads/file/kagamonalu.pdfIn PDF document text
    • https://xtrafitcoaching.com/www/images/files/gabosorixukukikizad.pdfIn PDF document text
    • https://anjingliar.com/contents/files/jotidorab.pdfIn PDF document text
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612f101f1f00e---fodotaxujimapesedat.pdfIn PDF document text
    • http://bearings-home.com/userfiles/file/30676641290.pdfIn PDF document text
    • https://sgcaregiver.org/contents/files/fasagexa.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16134e0de1dbe1---98875784588.pdfIn PDF document text
    • http://www.verneteco.com/ckfinder/userfiles/files/rixod.pdfIn PDF document text
    • https://iringmalaysia.com/ckfinder/userfiles/files/xazajobabi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=brawl+maker+mod+apkPDF 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_off0000cf7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCF7C 10320 bytes
SHA-256: d12fcd9bd6950befd81e5168f08a04b3a004fa0bb6b2646e7560f15ad82dc564
font_01_sfnt_off0000e6cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6CF 18120 bytes
SHA-256: 14471255257e08093d208ab63cce0232b96c83197cd188b8d0f7319b48f2991f
font_02_sfnt_off00011593.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11593 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1