Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb5db6471b041ea7…

MALICIOUS

PDF

71.5 KB Created: 2021-10-05 22:51:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: ae1938931bd9368693a93b3a3589e91a SHA-1: ed1792960a12ce568e3547c2ea82f554a2681d2d SHA-256: fb5db6471b041ea7f3b3d1af489534075965fb2341c1aa4e3428a6ab0dc8cf9d
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to compromised WordPress sites and disposable domains, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated, preventing a clear understanding of its specific lure, but the overall structure and URL analysis point to a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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 https://inwebjor.ru/uplcv?utm_term=how+to+make+variable+description+table+in+java PDF link annotation
    • http://lightofislamonair.org/uploads/files/52462846958.pdfIn PDF document text
    • http://jfac.kr/ckfinder/userfiles/files/bipesefa.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130dcfe4ee2b---39683661937.pdfIn PDF document text
    • http://hillsdalehorseboarding.com/ckfinder/userfiles/files/lakevupek.pdfIn PDF document text
    • http://clinicaveterinariailmarzocco.it/userfiles/files/20214794752.pdfIn PDF document text
    • http://sameiroeventos.pt/ficheiros/55682624325.pdfIn PDF document text
    • http://fotografieindex.nl/images/uploads/71715782522.pdfIn PDF document text
    • http://www.coverseg.com/uploads/ckfinder/files/netarizifokefazilibe.pdfIn PDF document text
    • http://birkhoffhi.com/userfiles/files/41708318561.pdfIn PDF document text
    • http://feuerwehrobrigheim.de/upload/files/fopor.pdfIn PDF document text
    • http://liveranigioielli.it/userfiles/files/2835359550.pdfIn PDF document text
    • http://epmachine.ru/d/files/bexul.pdfIn PDF document text
    • https://brokenspoke.com/wp-content/plugins/super-forms/uploads/php/files/a9fbc4f9489f7ce243ff6697a2702ca3/5448659560.pdfIn PDF document text
    • http://aotmoo.com/uploadfile/files/20210923_180800.pdfIn PDF document text
    • http://apicn.net/upload/files/43398953043.pdfIn PDF document text
    • http://cascad-trans.ru/files/80746549767.pdfIn PDF document text
    • http://dh-life.com/ckfinder/userfiles/files/51690614362.pdfIn PDF document text
    • http://syarmarka.ru/userfiles/files/36694599502.pdfIn PDF document text
    • https://www.accidentinjuryalbuquerque.com/wp-content/plugins/super-forms/uploads/php/files/bspqhd1bq4jeqmjfhdcbi3ejf2/52590143488.pdfIn PDF document text
    • https://ladangmimpi2.com/contents/files/xatinobuj.pdfIn PDF document text
    • http://prestopc.it/upload/file/pogometibad.pdfIn PDF document text
    • http://jlm-kg.com/uploads/file/53689051798.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_off0000b308.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB308 16036 bytes
SHA-256: 5516c72922e249f98439214a36982a5529cbe2cdde2d8c72f22f287047bebfc2
font_01_sfnt_off0000dc26.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDC26 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f43d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF43D 11180 bytes
SHA-256: dc4532474cf9f33287a64b48f23ba3e056a2caff7f1d1d3f2f005cf1cd7cc4e9