Malicious PDF — malware analysis report

Static analysis result for SHA-256 f8bb532bc63aff1c…

MALICIOUS

PDF

69.5 KB Created: 2021-09-22 20:38:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: a3a941f89d82ae131369612a584013e3 SHA-1: 695c052635675291bed56722a027ffc0c938f8fd SHA-256: f8bb532bc63aff1c60cef65878a75a3154e35820481bc48f6e4006ba8d00db85
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ClamAV and an ML classifier, with heuristics indicating embedded JavaScript and external URI links. The PDF structure suggests it's designed as a link farm, with many distinct hosts pointing to PDF files, likely to obscure the true malicious destination. The presence of embedded JavaScript further supports its role in executing malicious actions, such as redirecting users to phishing sites or downloading further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9837

Heuristics 6

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://studioriggio.it/userfiles/files/finimuzotutevujolepozev.pdf In PDF document text
    • http://amunt.madteam.net/ckfinder/userfiles/files/27584468582.pdfIn PDF document text
    • http://posuni.com/userfiles/file/30862828841.pdfIn PDF document text
    • http://dd-eng.com/files/files/7428634254.pdfIn PDF document text
    • http://www.oneworldkarate.com/fckeditorimages/userfiles/file/vizopunikapul.pdfIn PDF document text
    • https://bokaichenyu.com/upload/files/42266374613.pdfIn PDF document text
    • http://clear-es.net/yamituki-n/uploads/files/93183429168.pdfIn PDF document text
    • https://2acontractor.it/images/file/rokejew.pdfIn PDF document text
    • http://tufaghanafc.com/js/ckfinder/userfiles/files/dakifofuginalo.pdfIn PDF document text
    • https://heritran.vn/uploads/news_file/85874887875.pdfIn PDF document text
    • https://stakeoutllc.com/wp-content/plugins/super-forms/uploads/php/files/906aa55fc8040aefefef697eace039d7/wivenegesad.pdfIn PDF document text
    • https://www.hmgfinance.com/ckfinder/userfiles/files/jalenepadijemoli.pdfIn PDF document text
    • http://patriabrno.cz/userfiles/files/69007364857.pdfIn PDF document text
    • http://bkmarine.net/ckfinder/userfiles/files/1631850510.pdfIn PDF document text
    • https://bilegt.mn/userfiles/files/52144698393.pdfIn PDF document text
    • http://decamiones.com/userfiles/file/nomomanozosuludiz.pdfIn PDF document text
    • http://thedewakohchang.com/image/upload/File/evurutek.pdfIn PDF document text
    • http://jamones-luna.shopcloud.es/ckfinder/userfiles/files/77131702442.pdfIn PDF document text
    • http://jyjjapan.jp/files/ckeditor/files/mojazagumebep.pdfIn PDF document text
    • http://grupafurman.pl/!mag2011/userfiles/file/vasanetifemuk.pdfIn PDF document text
    • https://hogozaty.com/ckfinder/userfiles/files/zematepijunadedikogejut.pdfIn PDF document text
    • http://badischer-kunstverein.de/ckfinder/userfiles/files/96447253595.pdfIn PDF document text
    • https://healthresearchinstitute.net/userfiles/file/64948657822.pdfIn PDF document text
    • http://www.sictombbi.fr/ckfinder/userfiles/files/57665736171.pdfIn PDF document text
    • http://spad.kr/userData/ebizro_board/file/roxumegobe.pdfIn PDF document text
    • https://travelone.ae/userfiles/files/kagonixikatufanagixud.pdfIn PDF document text
    • http://dinskayarealty.ru/media/file/gofazizisilezipimuvewome.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1KS0DP0cxss/uplcv?utm_term=airjack+wifi+hackPDF 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_off0000b570.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB570 10056 bytes
SHA-256: bb4cc5ea3b46019bbbe7e783bb8c2ff012477b8affbd0923c7d846f1b325355c
font_01_sfnt_off0000cbe3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBE3 14632 bytes
SHA-256: 46b2d39cf30d76d345253e7614ab9504462d63d262f5217476493c5b47b4ae10
font_02_sfnt_off0000f0a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF0A9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1