Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a4781202e22de50…

MALICIOUS

PDF

72.3 KB Created: 2021-09-17 09:54:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: e7977b8eb7f8ee7b7556aa26a482c8c6 SHA-1: 1e3e23d922263047264767cff5f99913d08e86f8 SHA-256: 5a4781202e22de50a7edcb057c5c16ab668b4fa21e9d78732e57c7c2a87484c8
156 Risk Score

Malware Insights

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

The PDF was flagged by ClamAV as 'Pdf.Phishing.Trojan' and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with several URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. No scripts were extracted, but the structure and URL analysis strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://hung168.tw/UserFiles/files/bujezoziniromujefeja.pdf In PDF document text
    • https://podgoricki-klub.me/userfiles/file/nuxapivamivewez.pdfIn PDF document text
    • http://dalboncostruzioni.it/userfiles/files/jovikaxevab.pdfIn PDF document text
    • https://atamergranit.com/userfiles/file/4992611365.pdfIn PDF document text
    • http://lecieldesandes.fr/ckfinder/userfiles/files/47408596674.pdfIn PDF document text
    • http://comicpapyrus.com/wp-content/plugins/super-forms/uploads/php/files/79eb2110dc5166a4cda688ed9aa999f0/71925131852.pdfIn PDF document text
    • http://kleinschaden-expert.de/userfiles/file/jevekovumilaneb.pdfIn PDF document text
    • https://calienglish.com/ckfinder/images_store/files/74615542394.pdfIn PDF document text
    • http://www.loicadesacavem.pt/wp-content/plugins/formcraft/file-upload/server/content/files/1612fddd7a649a---86569777613.pdfIn PDF document text
    • https://fertilizerproductionprocess.com/d/files/tojenizelimugibizusaga.pdfIn PDF document text
    • http://dongshengcable.com/images/upload/File/73614796522.pdfIn PDF document text
    • http://fujieshubao.com/zk/UploadFile/file/2021090123380673499.pdfIn PDF document text
    • http://kasintorn.com/images/upload/files/ridilifapi.pdfIn PDF document text
    • https://highfieldhousehotel.net/nbloom/fckuploads/file/jufodozovi.pdfIn PDF document text
    • https://crossfitbeeshark.ro/app/webroot/files/userfiles/files/28914661275.pdfIn PDF document text
    • http://4998horo.gmmwireless.com/contents/files/pogewogigo.pdfIn PDF document text
    • https://www.denisonlandscaping.com/wp-content/plugins/formcraft/file-upload/server/content/files/16143b32213739---41266770792.pdfIn PDF document text
    • https://tfnd.org/wp-content/plugins/super-forms/uploads/php/files/4d831aa41943c239de19a56075764f6f/jenusofevakom.pdfIn PDF document text
    • http://emirates-offshore.com/uploads/image/file/bisajokutisiro.pdfIn PDF document text
    • https://ipic.vn/userfiles/file/jomewo.pdfIn PDF document text
    • http://peaceinsrilanka.lk/userfiles/file/4221650912.pdfIn PDF document text
    • https://a-guskov.ru/uploads/files/rufefe.pdfIn PDF document text
    • http://preiss.at/upload_files/files/4089002955.pdfIn PDF document text
    • http://futsalcb.cz/picture/vtextu/file/42636810977.pdfIn PDF document text
    • http://wdnederland.nl/file/wafiretixanomis.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=how+to+notification+sound+androidPDF 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_off0000bb41.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB41 10468 bytes
SHA-256: c7a93a5b6205a4d9b7d5c9a0fd212c642ec135a29d80b5ccd9004ed991fb0510
font_01_sfnt_off0000d325.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD325 15900 bytes
SHA-256: a1f04cd68212c3409db15b3fd0dcdabaa0e690849bcf1fb2c3a3ea20a7991621
font_02_sfnt_off0000fbab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBAB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1