Malicious PDF — malware analysis report

Static analysis result for SHA-256 0150089ee5a4db81…

MALICIOUS

PDF

73.5 KB Created: 2021-09-11 09:07:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 435c580b1c24006b2736b69eacebaced SHA-1: e0f88d5b87d3053a0e6726c2fb4800a036f55232 SHA-256: 0150089ee5a4db8185f5853cf410dec21ef50e24f8a25573323f1e992b373572
156 Risk Score

Malware Insights

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

The PDF contains a link farm with numerous embedded URLs, many pointing to disposable hosting or compromised CMS uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. The document body is heavily obfuscated and unreadable, but the heuristic firings clearly point to a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://brbud.pl/userfiles/file/31465639119.pdf In PDF document text
    • https://www.vasutaszeneiskola.hu/ckfinder/userfiles/files/nidunafufabiso.pdfIn PDF document text
    • http://cloudinfo01.smartevolve.com/images/ckeditor/files/72766967800.pdfIn PDF document text
    • http://mobilenmr.com/files/files/11664359140.pdfIn PDF document text
    • https://patoman.ro/ckfinder/userfiles/files/zoximagofanefe.pdfIn PDF document text
    • https://franchise-vietnam.com/app/webroot/img/files/36307646029.pdfIn PDF document text
    • https://betonwerkendejonge.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16134e68b48968---48263151208.pdfIn PDF document text
    • http://chaukitchen.com/uploads/files/92417442626.pdfIn PDF document text
    • https://muzeumkonstancina.pl/attachments/file/buduzagapux.pdfIn PDF document text
    • http://dralituncer.net/userfiles/file/21644071872.pdfIn PDF document text
    • http://conflictfreeelectronics.com/ourprojects/chowki/UserFiles/renuka/file/fetowevadojemirikubo.pdfIn PDF document text
    • https://gaadalagi.com/contents/files/4042538447.pdfIn PDF document text
    • https://divetechmarine.com/contents/files/34962731553.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1612f783b6bc0a---noponadojo.pdfIn PDF document text
    • http://boissee.fr/userfiles/file/tenufubiketonap.pdfIn PDF document text
    • http://kpdb.org/userfiles/files/43741066735.pdfIn PDF document text
    • http://giadinhlaurenso.org/upload/files/jilobusutijuxotu.pdfIn PDF document text
    • http://phongkhamthienhoa.vn/images/files/54147618870.pdfIn PDF document text
    • http://canxetaianhduc.com/images/file/36882460977.pdfIn PDF document text
    • http://emiem.pl/public/upload/ckfinder/userfiles/files/88549912862.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/16134c5324888c---sisikukalusasaxupukela.pdfIn PDF document text
    • http://www.telsercom.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613657781c6f4---49419573470.pdfIn PDF document text
    • http://www.predoisiasociatii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613749e16b7da---85601112127.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=mobile+legend+mod+apk+android+1PDF 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_off0000bcfe.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCFE 10744 bytes
SHA-256: 0e22f627914f79b16ad9ffda53554864e94a4b2c2365ca65d5d9adc2aac59004
font_01_sfnt_off0000d535.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD535 16848 bytes
SHA-256: c25189535813d544ec808e2393d5f6127cd73119673fb93d08b36b0533594c58
font_02_sfnt_off00010052.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10052 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1