Malicious PDF — malware analysis report

Static analysis result for SHA-256 818ad603950db384…

MALICIOUS

PDF

76.2 KB Created: 2021-09-17 02:44:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 0baac3ef6c885eed35aad8768326a7f0 SHA-1: 787bea98c4f27a2796ee073bbf4d4474e8edbaa3 SHA-256: 818ad603950db38405e649b13d6045fccf1f5930bba9a4630ded03b71594f197
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. It contains numerous embedded URLs, many of which point to PDF files on various domains, suggesting a link farm or SEO poisoning attempt. One heuristic specifically identified a 'link farm on disposable hosting', indicating a likely malicious intent to redirect users or manipulate search results.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://888spirits.com/userfiles/file/20980537780.pdf In PDF document text
    • https://gtselect.fr/ckfinder/userfiles/files/bubikemikojuzobutonukome.pdfIn PDF document text
    • http://conomiya.com/images/uploadedimages/file/ruremifipekov.pdfIn PDF document text
    • http://www.wallisandemmanuel.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c3ce34436a---monurafugazerovixisasob.pdfIn PDF document text
    • https://www.esfa.bg/root/ckfinder/userfiles/files/sujim.pdfIn PDF document text
    • http://guitarenko.fr/img/files/80483212668.pdfIn PDF document text
    • http://dc-42351dc5a6b3.prshots.es/uploads/userfiles/1630493241/files/gupidofenagajufiwazejeziv.pdfIn PDF document text
    • http://jsdarvin.com/files/xupaguzaduze.pdfIn PDF document text
    • https://artistprasanna.com/userfiles/file/43220533458.pdfIn PDF document text
    • http://diadiemvui.com/upload/files/govafewizazapuxikurabunet.pdfIn PDF document text
    • http://alexdisinfestazioni.com/userfiles/files/82808024612.pdfIn PDF document text
    • http://k1a.ru/images/files/file/tupaxolozolazibe.pdfIn PDF document text
    • http://meimagedance.tw/ufiles/files/wobopawosediwatubolupir.pdfIn PDF document text
    • https://mauspro.net/upload/files/51416338910.pdfIn PDF document text
    • http://tatvideo.ru/ckfinder/userfiles/files/690058296.pdfIn PDF document text
    • http://wellgroup.cz/UserFiles/File/10989162132.pdfIn PDF document text
    • http://tvoirostov.ru/ckfinder/userfiles/files/10569217949.pdfIn PDF document text
    • http://digitalpolicycouncil.com/imagenes/file/dabexoselisapogorelajel.pdfIn PDF document text
    • https://gionggiacam.com/ckfinder/userfiles/files/sepepekujatageno.pdfIn PDF document text
    • http://cheliabinsk.realxenon.ru/uploads/files/zenalovitem.pdfIn PDF document text
    • https://jpjplumbingandheating.com/FCKeditor/file/74338575049.pdfIn PDF document text
    • https://gmnavarra.es/ckeditor/files/wemokawezabasegosunazabo.pdfIn PDF document text
    • http://pegastelco.com/pictures/files/5051873592.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=vikings+season+1+full+episodesPDF 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_off0000c2a8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC2A8 18552 bytes
SHA-256: 9bae6f431fa7c4dda342ed9552e07bc801f0c460edf4f960552dfb215fa78ac0
font_01_sfnt_off0000f2d8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2D8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010aef.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10AEF 10688 bytes
SHA-256: ef6518ca71158abe3737488f6ee9e40ece018dbd8c01a312b6e642651f4febd4