Malicious PDF — malware analysis report

Static analysis result for SHA-256 51ad03bdc172982e…

MALICIOUS

PDF

96.7 KB Created: 2021-09-01 11:13:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: d43b52ee667cb0b8a394079103131686 SHA-1: b4229a7b575b19f06bcbedb3799ac2639d2d3840 SHA-256: 51ad03bdc172982e3169fd95d9a06c77311b9542473fc0b055e81877ecace019
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to other PDF files hosted on compromised websites, indicating a link farm or distribution mechanism. The ClamAV detection and ML classifier strongly suggest malicious intent, likely related to phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a malicious document designed to lure users or manipulate search engine results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9965

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://kiaavcilar.com/upload/ckfinder/files/woduradujajimasipek.pdf In PDF document text
    • http://seasonsblinds.com/uploads/ckfinder/userfiles/files/zunekafuvomejolegaseliki.pdfIn PDF document text
    • http://namngonviet.com/user-/files/46300972381.pdfIn PDF document text
    • https://baongochoa.com/upload/file/sizugubunenuxapudef.pdfIn PDF document text
    • http://mujuerp.com/uploads/ckeditor/files/20210619185641.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bead1992680.pdfIn PDF document text
    • https://rybczewice.pl/userfiles/file/12291884564.pdfIn PDF document text
    • https://www.sadcmedia.com/wp-content/plugins/super-forms/uploads/php/files/1gnsfvg92v8q4hbsose1hdfgpd/bukewatesodapudeg.pdfIn PDF document text
    • https://rainbowfurnitures.com/files/files/19688634476.pdfIn PDF document text
    • https://feniks9.ru/ckfinder/userfiles/files/73310755833.pdfIn PDF document text
    • http://www.mostenpo.jp/userfiles/files/21593216385.pdfIn PDF document text
    • http://itnetworkconsultingsf.com/helpdesk/app/webroot/img/userfiles/files/53402056225.pdfIn PDF document text
    • http://findmealocalpainter.com/insurazon/admin/userfiles/file/86877847059.pdfIn PDF document text
    • http://akcjonariusz.com/UserFiles/file/74543547884.pdfIn PDF document text
    • http://think6.net/ckfinder/userfiles/files/20210814023456.pdfIn PDF document text
    • http://gw73patriots.com/clients/1/1e/1ed986c9d410becccfd9995a8318e329/File/27343844046.pdfIn PDF document text
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1607ac34e3b57d---rarekex.pdfIn PDF document text
    • http://lasfyy.com/uploadfile/file/20210602063159277.pdfIn PDF document text
    • http://giasuthanhdat.vn/Images_upload/files/peserikifudobabedepor.pdfIn PDF document text
    • http://chsbicentennialclassof1976.com/clients/c/c2/c283bfa2537a82fb79a670aa087b4bd4/File/98810423845.pdfIn PDF document text
    • https://residenciasanamaro.es/userfiles/files/zijajibituwupodasoze.pdfIn PDF document text
    • https://puppometalli.eu/file/zavedoboxew.pdfIn PDF document text
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bee1f6bd2f1---19938799895.pdfIn PDF document text
    • https://nhahangphongcanh.com/uploads/files/26089457158.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=wow+classic+warlock+demonology+leveling+buildPDF 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_off00011259.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11259 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00012a6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A6B 18656 bytes
SHA-256: ef969f991cf7df275961c545d62ce5dc28de6b4b18dfd68fc7692c2e6dfd7274
font_02_sfnt_off00015acf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15ACF 11204 bytes
SHA-256: 2ec8d0e9125b9c5fe1743f16548d4aa540d515209917aebe61543b03ebaa37f7