Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1758c190cd1e9c8…

MALICIOUS

PDF

73.4 KB Created: 2021-09-25 22:04:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 830dc0b436c7c32d288abb3c22cdcff8 SHA-1: 6ca96ceef9ff6616976ff6bde405569d5594899c SHA-256: d1758c190cd1e9c81b0632245488cda1666a15e1f0a2081f87d82cdc6623dc56
126 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, containing numerous links to external sites, many of which are hosted on disposable domains. The document body is heavily obfuscated and appears to be generated content rather than user-readable text, further supporting a malicious intent to redirect users to potentially harmful URLs.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://micruts.org/userfiles/file/wakoraxatu.pdf In PDF document text
    • http://csc0451.com/userfiles/file/20210905222943_xmbaem.pdfIn PDF document text
    • http://ingmarcofaedi.com/userfiles/files/94052133899.pdfIn PDF document text
    • http://xn--sanitrprofi-p8a.ch/fckeditor/editor/images/file/tokufogilobisixuwuworejok.pdfIn PDF document text
    • http://raylutickenterprises.com/userfiles/files/savemibadebiwenadi.pdfIn PDF document text
    • https://sbmhavacilik.com/userfiles/file/gaxadefanir.pdfIn PDF document text
    • http://www.investinwielkopolska.pl/application/lib/ckfinder/userfiles/files/17868441295.pdfIn PDF document text
    • https://renhedc.com/uploads/files/202109231547373852.pdfIn PDF document text
    • https://vadihosting.com/calisma2/files/uploads/29059844334.pdfIn PDF document text
    • http://brothersaluminium.com.np/wp-content/plugins/formcraft/file-upload/server/content/files/1614db3b649847---foluf.pdfIn PDF document text
    • http://www.neoneophytou.com/ckfinder/userfiles/files/taturerajosok.pdfIn PDF document text
    • http://platypusspot.org/uploads/ckfinder/userfiles/files/kaxoluwiwid.pdfIn PDF document text
    • http://richmore.kr/uploadfile/fckeditor/file/jozakixokorejetarekigus.pdfIn PDF document text
    • http://mayjack.com/upload/files/jovulosa.pdfIn PDF document text
    • http://marketypik.pl/zdjecia/fck/file/ragivofetimunawuvoweronu.pdfIn PDF document text
    • https://taiwancy.com/app/webroot/userfiles/files/nizilosugopij.pdfIn PDF document text
    • http://thienthaopc.com/upload/FCK/file/watex.pdfIn PDF document text
    • http://www.megasaludips.com/wp-content/plugins/formcraft/file-upload/server/content/files/161388f54ce462---jexemujudanevesawigimi.pdfIn PDF document text
    • http://aotwcasino.com/ckfinder/userfiles/files/vibevibekaxodafujukanire.pdfIn PDF document text
    • http://5thaveseniors.org/userfiles/file/lidomisagajepuleninu.pdfIn PDF document text
    • http://pietroquatriniarchitetto.eu/userfiles/files/jopigavudoreroketidew.pdfIn PDF document text
    • http://spl-designs.com/ckfinder/userfiles/files/duxoku.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=how+to+make+purple+with+yellowPDF 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_off0000b96c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB96C 18100 bytes
SHA-256: 1b628483b5a648fa824391fcbde815205239e66f3f1efa1631af78e82b3ad094
font_01_sfnt_off0000e79f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE79F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ffb6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFB6 10628 bytes
SHA-256: bf3f4e5d6d184ec3e8b287804fa6fb6b19f497c863143ec28469f5ee8835d951