Malicious PDF — malware analysis report

Static analysis result for SHA-256 dffc5853817b0807…

MALICIOUS

PDF

75.4 KB Created: 2021-09-22 10:21:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: d02ce8b2876bfaab12aed4bfbd297b00 SHA-1: 3d4dd9988c21167d88738b119970902918f2aa56 SHA-256: dffc5853817b08072bdef405c53cea5da941dc642d708bd3a8a1267590ca304b
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file contains a link farm directing users to multiple external websites, some of which are hosted on compromised CMS platforms. The ML classifier strongly indicated maliciousness, and the presence of numerous links on disposable hosting suggests an attempt to distribute malicious content or phish users. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://asi-filter.pl/files/file/43867575185.pdf In PDF document text
    • http://jiin-torng.com/uploadfiles/20210912174645.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/1612efe82407b4---10804062924.pdfIn PDF document text
    • https://vicareyou.com/userfiles/file/13508965575.pdfIn PDF document text
    • https://bnovum.hu/downloads/35218656164.pdfIn PDF document text
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/16135e3ad34510---nibajukifumodegifofek.pdfIn PDF document text
    • http://www.saaegfpolis.org.br/ckfinder/userfiles/files/kabenofo.pdfIn PDF document text
    • http://gzcaifeilai.com/ckfinder/userfiles/files/202109130233415015.pdfIn PDF document text
    • http://teormech.ru/teormech/usrimg/file/widow.pdfIn PDF document text
    • http://ergo-logo-bamberg.de/userfiles/file/74226774202.pdfIn PDF document text
    • http://polipack.ru/content/file/xuwanizadu.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bc53c7a61b---vuxufunizinesakugimodimo.pdfIn PDF document text
    • http://cityclick.it/userfiles/files/topopuxewibudet.pdfIn PDF document text
    • https://listocrm.com/userfiles/files/38626693729.pdfIn PDF document text
    • http://ohmytour.kr/FileData/ckfinder/files/20210918_A0D6992098938362.pdfIn PDF document text
    • http://wahluenfty.com/userfiles/jilofogasubukiwedo.pdfIn PDF document text
    • http://zeguvietnam.com/uploads/ckfinder/files/50222132387.pdfIn PDF document text
    • https://hockeymro.ca/docs/file/divubujerukijimizo.pdfIn PDF document text
    • http://umrllc.com/userfiles/files/53410197103.pdfIn PDF document text
    • https://ijtm.in/userfiles/file/filori.pdfIn PDF document text
    • http://csc021.com/userfiles/file/20210922143056_9b9pbr.pdfIn PDF document text
    • http://demo755.webbazaar.com/uploads/60338614576.pdfIn PDF document text
    • http://kryotherapie.net/neu/userfiles/file/pevijikojeduvumexu.pdfIn PDF document text
    • http://bioaec.com/userfiles/files/wagomejipawilozajura.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/161355bd65af44---9880765753.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=sex+games+for+couples+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_off0000bb13.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB13 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d325.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD325 19232 bytes
SHA-256: b0a4f9bd279e07559e00cd7634b2ef65dabec215dfbb4bbc77b32ce4a09ca441
font_02_sfnt_off00010518.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10518 11040 bytes
SHA-256: 723d17859967b38d317e72f3362aeaa0d0e52a5a61198c3aec952ccdb4c1b971