Malicious PDF — malware analysis report

Static analysis result for SHA-256 47f8c26cecdf2f6b…

MALICIOUS

PDF

73.5 KB Created: 2021-09-13 08:29:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 4995d6eedffd61f4252ae42ab0840ad7 SHA-1: a1d9a967fd4e32fdb5a855ffecf022da7cc4874e SHA-256: 47f8c26cecdf2f6b4f809bc860b6465a91d7c3e4ae1dfc6244a0af49b3909d8d
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised WordPress upload directories and disposable hosting. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://www.hkwebdesign.com.hk/wp-content/plugins/formcraft/file-upload/server/content/files/161305498b7222---83946348148.pdf In PDF document text
    • http://pieseclimaauto.com/files/file/40717394360.pdfIn PDF document text
    • http://g-shocktou.com/user_file/file/wuresepixadixux.pdfIn PDF document text
    • http://monterroso-construpuntos.com/campannas/file/gumowevomipidudosuse.pdfIn PDF document text
    • https://zohopin.com/calisma2/files/uploads/fukomipudadaxeji.pdfIn PDF document text
    • http://2990592.ru/ckfinder/userfiles/files/puramezikosufiwefolot.pdfIn PDF document text
    • https://badeluxe.com/userfiles/files/16855601590.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/16132b55ca2f1a---10116009601.pdfIn PDF document text
    • http://tythb.com/uploadfile/files/80948273312.pdfIn PDF document text
    • https://proff-doors.ru/wp-content/plugins/super-forms/uploads/php/files/51f0fb014aa45ea58962b0918742e733/72267320384.pdfIn PDF document text
    • https://www.drserapkagan.com/wp-content/plugins/super-forms/uploads/php/files/1jrctaisn83rmhu0noi5lq1prv/gebetizoleroguv.pdfIn PDF document text
    • https://dnm.tw/uploads/files/202109120909276450.pdfIn PDF document text
    • https://iohrp.org/f_files/files/lapovonanawakizugedega.pdfIn PDF document text
    • https://newline-eg.com/userfiles/file/94065514563.pdfIn PDF document text
    • http://srcchaika.ru/files/uploads/files/57059036877.pdfIn PDF document text
    • http://dnt-mayak.ru/content/File/41708766447.pdfIn PDF document text
    • https://moma-restaurant.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613843608514b---31310625851.pdfIn PDF document text
    • http://kliknetezde.cz/admin/obrazky/file/gukuboperis.pdfIn PDF document text
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161305af4db015---84986153233.pdfIn PDF document text
    • http://szwygs.com/upload/88498604896.pdfIn PDF document text
    • http://zhjpharm.com/upload/files/gowod.pdfIn PDF document text
    • https://www.mercato.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1613d184d34097---zetupetikikezitubebijug.pdfIn PDF document text
    • https://bomando.bomsolar.com/uploadfiles/files/varikarure.pdfIn PDF document text
    • http://aatmicscience.org/asuserfiles/file/manasitelataxobivunani.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=cricket+real+gamePDF 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_off0000bdee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBDEE 16712 bytes
SHA-256: fed6d7142bfba8911d2814f10c9ffea9334998ddc8a9ea531fcdb892751a0e71
font_01_sfnt_off0000e92e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE92E 10304 bytes
SHA-256: 4a80b78f24ec5820d2230fba6dc426e11bc2fd0a7b593a0eb4cfc5477f891acb
font_02_sfnt_off00010077.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10077 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1