Malicious PDF — malware analysis report

Static analysis result for SHA-256 ed26b5e8701da89c…

MALICIOUS

PDF

81.0 KB Created: 2021-09-11 08:22:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ef4b006152ed513138da42dee95f5fc7 SHA-1: 2f74ec802650038b1a1214f7cc85923ece98d9eb SHA-256: ed26b5e8701da89cebdf638b7eca7b455cbf7219e1937e285c58b63e517d6766
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was identified as malicious by ClamAV and an ML classifier. It contains a link farm pointing to numerous PDF files hosted on various domains, many of which appear to be compromised or disposable. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using such domains for hosting malicious content. The presence of multiple external URIs suggests an attempt to redirect the user to potentially harmful content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://usaoxin.com/userfiles/2021-9/file/9467669512.pdf In PDF document text
    • http://gpmpoolandspa.com/ckfinder/userfiles/files/peromozazojur.pdfIn PDF document text
    • https://grandplaza.bg/uploads/assets/file/41718287605.pdfIn PDF document text
    • http://sp3siemianowice.pl/userFiles/files/8677956694.pdfIn PDF document text
    • http://yds-wcv.jp/free_images/files/23059835300.pdfIn PDF document text
    • http://dotbamboo.com/file_media/file_image/file/jonejubeleroz.pdfIn PDF document text
    • https://huanghecables.com/d/files/bixinebofawed.pdfIn PDF document text
    • http://ryyw.com/upload/files/2021/09/202109101705405121.pdfIn PDF document text
    • https://relleno-acidohialuronico.com/wp-content/plugins/super-forms/uploads/php/files/ffca0006440a583f53bddf2f5f23bd38/52989787828.pdfIn PDF document text
    • https://marlin-aquarium.ru/ckfinder/userfiles/files/1124711564.pdfIn PDF document text
    • http://mcap.cz/images/uploadedimages/file/91668088394.pdfIn PDF document text
    • https://hglobaltourb2c.com/FileData/ckfinder/files/20210901_E6829783A0C75180.pdfIn PDF document text
    • https://almuhja.ps/ckfinder/userfiles/files/famizorarigebeluxa.pdfIn PDF document text
    • http://heatexchangersolution.com/upload_fck/file/2021-9-7/20210907135545409720.pdfIn PDF document text
    • https://pepsima.biz/files/file/fidefetarexe.pdfIn PDF document text
    • https://www.formwork.co.uk/wp-content/plugins/super-forms/uploads/php/files/bmc74bkp76pg427gg5nu51cr2m/84411548889.pdfIn PDF document text
    • http://ciaooo.ru/uploades/userfiles/file/66816898332.pdfIn PDF document text
    • http://www.its-dph.cz/admin/fckeditor/editor/userfiles/file/zagezekugadigofuwuxod.pdfIn PDF document text
    • http://massimobertoarchitetto.com/userfiles/files/21599666474.pdfIn PDF document text
    • https://unovosti.tv/ckfinder/userfiles/files/97743351068.pdfIn PDF document text
    • http://tatugigo.com/ckfinder/userfiles/files/lubisidaburaku.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613038a9a3fe4---27089020829.pdfIn PDF document text
    • http://hieuchuan.com/upload/files/53319789646.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=final+fantasy+3+mapsPDF 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_off0000d9b6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9B6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f1c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF1C8 17596 bytes
SHA-256: 99631818439a80873187f77b577cd12c7caeb2db84f4f02fd531ba9879b8977f
font_02_sfnt_off00011f0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F0B 10432 bytes
SHA-256: f9f8d94e43dc72259c3f723fe17822d24fda00c3dfcdcff9743fcece511da899