Malicious PDF — malware analysis report

Static analysis result for SHA-256 543ae93793fe070c…

MALICIOUS

PDF

83.0 KB Created: 2021-09-10 03:48:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 65525709afbe333c4776018f188f8cc2 SHA-1: a607b56dfdf97fde292837f4498f03bd4765ce79 SHA-256: 543ae93793fe070c3373147b5ea6e0a2b92a61448b0f32e3700c11484a0545ea
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

This PDF was flagged by multiple heuristics as malicious, including a link farm detection and an ML classifier. The document body is heavily obfuscated, but the presence of numerous embedded URLs, many pointing to potentially disposable domains, suggests a phishing or redirection attempt. The ClamAV detection further confirms its malicious nature, likely as a phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://chrmglobal.com/userfiles/file/voboxa.pdf In PDF document text
    • http://wksystems.net/HotelEstimator/userfiles/file/pinuvijazata.pdfIn PDF document text
    • https://nikken-engineer.jp/export/sd205/www/jp/r/e/gmoserver/8/6/sd0748886/nikken-engineer.jp/fckeditor/upload/file/kadisezegot.pdfIn PDF document text
    • http://ricettebiagi.it/uploads/assets/file/boviposef.pdfIn PDF document text
    • https://www.rosebankprimary.co.za/inc/ckfinder/userfiles/files/45603719447.pdfIn PDF document text
    • http://yuc-fac.com/uploadfiles/20210910000855.pdfIn PDF document text
    • https://cristalparkhotel.com/ckfinder/userfiles/files/9467731421.pdfIn PDF document text
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/b14b78921d5e0ea141f1e85804f1fead/13489759321.pdfIn PDF document text
    • http://honyi.tw/ckfinder/userfiles/file/wojavoki.pdfIn PDF document text
    • https://snf.styleguides.ch/userfiles/files/regukoguje.pdfIn PDF document text
    • https://10kshot.com/customerinterview/ckfinder/userfiles/files/40454030735.pdfIn PDF document text
    • http://nhactheducthammy.com/upload/files/lisagadepez.pdfIn PDF document text
    • http://dienlanhhuubinh.com/upload/files/18635290997.pdfIn PDF document text
    • http://vinhthuan.vn/upload/files/64823343509.pdfIn PDF document text
    • http://jongauger.com/ckfinder/userfiles/files/vetow.pdfIn PDF document text
    • http://jutaek.humenia.com/upload/userfiles/2021/09/files/210906054427.pdfIn PDF document text
    • http://dar-tom.pl/userfiles/file/pilutuxetakimizavumi.pdfIn PDF document text
    • http://donkaew-furniture.com/ckfinder/userfiles/files/sodipofeximagobewuwopetas.pdfIn PDF document text
    • https://congchungnguyenlieu.vnpec.xyz/uploads/files/60548718161.pdfIn PDF document text
    • http://timebank.ru/sites/default/files/photos/pagefile/bifenuderugigofowami.pdfIn PDF document text
    • http://metalltechnik-kutschi.at/4391190261.pdfIn PDF document text
    • https://coil.hk/upload/files/zebas.pdfIn PDF document text
    • http://darstin.com/userfiles/files/20749794816.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=reading+comprehension+year+4+pdfPDF 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_off0000dec1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDEC1 17592 bytes
SHA-256: 2fbb64afc9bba024e806fdd06a3b1b686919dd1951952a0da97bc774da49a655
font_01_sfnt_off00010c2b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C2B 11160 bytes
SHA-256: 2afd5d0025c593ffad3884734cbd1c06ca1f4c7e4a4d143c0cff47d785efcb03
font_02_sfnt_off000125dc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125DC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1