Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0fc58d3c4bec1b5…

MALICIOUS

PDF

81.5 KB Created: 2021-09-24 00:43:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 6dc86db724093fe58bae15f0fbcfdd9a SHA-1: bb1c516a3165ea160747b482da458c97d73c477c SHA-256: a0fc58d3c4bec1b51847c147d1649adf436a9c2b763bc14eebd6d79596d980ff
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to disposable domains and are structured as a link farm, a common tactic for distributing malicious content or conducting phishing campaigns. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly indicates this malicious intent.

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 http://naturalfurnish.com/userfiles/file/faraxuzukoxudatovis.pdf In PDF document text
    • http://mvpbuilding.com/userfiles/file/63882144027.pdfIn PDF document text
    • http://teewer.mn/ckfinder/userfiles/files/jekukudodi.pdfIn PDF document text
    • https://madeinstlucia.com/userfiles/files/terawum.pdfIn PDF document text
    • http://cz-synergy.cz/data/file/83777782029.pdfIn PDF document text
    • http://cecev.com/stockages/files/wimowawap.pdfIn PDF document text
    • http://rudolphi.nu/userfiles/file/14988379968.pdfIn PDF document text
    • https://netpage.info/userfiles/file/nenimawafegosezovigi.pdfIn PDF document text
    • https://christianklein.eu/Quansis/ckfinder/userfiles/files/xokekepuwu.pdfIn PDF document text
    • http://arenabilardo.com/data/_files/8195129231.pdfIn PDF document text
    • http://guchen.ru/d/files/16194901616.pdfIn PDF document text
    • http://usaoxin.com/userfiles/2021-9/file/towufe.pdfIn PDF document text
    • https://n95america.com/wp-content/plugins/super-forms/uploads/php/files/875a08a28283c3327d4a66a448754ec8/xisirisosepemul.pdfIn PDF document text
    • https://tecsal.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1614b5ffa9848d---katuxer.pdfIn PDF document text
    • http://zhihepvb.com/upload/ckimg/files/202109190648011307.pdfIn PDF document text
    • http://oxigensupplies.com/shipinc/userfiles/files/pakosazofoxumapojisizime.pdfIn PDF document text
    • http://biomax.shop/filespath/files/20210903033055.pdfIn PDF document text
    • https://xuanhongkhang.com/upload/files/31194128826.pdfIn PDF document text
    • https://uleiuri.ro/userfiles/file/xudekisonub.pdfIn PDF document text
    • http://jfe.hk/userfiles/fixajepis.pdfIn PDF document text
    • https://orangcar.com/app/webroot/upload/files/3330710121.pdfIn PDF document text
    • http://duhochoangthanh.com/upload/files/2529986798.pdfIn PDF document text
    • http://gattoneva.pl/pages/userfiles/file/rijofepidapa.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/FevRqgeaUVY/uplcv?utm_term=hawt+and+vawtPDF 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_off0000e107.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE107 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f919.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF919 16384 bytes
SHA-256: d194a2f649593406c21df1c4366ac4e118c5cf4c721e04e5839e5ae7f3b17359
font_02_sfnt_off00012352.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12352 9724 bytes
SHA-256: ad326ad88888b48a24fe29497148c7325b7c3a3c3eb1bc9a9c88857d088dbdc2