Malicious PDF — malware analysis report

Static analysis result for SHA-256 24490d0b6f0bc79d…

MALICIOUS

PDF

72.6 KB Created: 2021-09-13 16:51:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 582604258125a7bf9c9ee13e543cf527 SHA-1: 602e107b3e64cc79031aeaaa7bcf0bb768c50636 SHA-256: 24490d0b6f0bc79df0f5bf082e580031133a80f365408a0534860c3540a48b80
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external URIs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm. The ML classifier also flagged this PDF as malicious with high confidence. While no scripts were explicitly extracted, the nature of the link farm suggests it is intended to redirect users to malicious sites, potentially for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 5

  • 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 https://medvor.ru/uplcv?utm_term=bedtime+stories+in+marathi+pdf PDF link annotation
    • http://studiotecnicolari.it/userfiles/files/tukilikexawexapum.pdfIn PDF document text
    • https://www.mediawerf.nl/bundles/store24backoffice/ckfinder/userfiles/files/79400166613.pdfIn PDF document text
    • http://eduomania.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613ec0de7ff7b---85274234939.pdfIn PDF document text
    • http://kup-vino.cz/web/ckfinder/userfiles/files/31039457162.pdfIn PDF document text
    • http://efcosmetic.com/uploadfile/files/94298647695.pdfIn PDF document text
    • http://mevlanaasm.com/resimler/files/88950183551.pdfIn PDF document text
    • http://rotarytattoomachine.co/project-new/christianbook/upload_images/file/rapuwiwelifalazesi.pdfIn PDF document text
    • https://www.goldenplanet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/16136f53466ad1---gezatixezobexima.pdfIn PDF document text
    • http://knuhpharm.kr/userfiles/file/20210906044935.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/1613131c8d2687---66798213313.pdfIn PDF document text
    • https://bhiringisamsankalimandir.org/ckfinder/userfiles/files/lafuvunenapexisog.pdfIn PDF document text
    • http://zpkprzemysl.pl/ckfinder/userfiles/files/tawerarusewawudoz.pdfIn PDF document text
    • http://sterenstein.ru/userfiles/file/muleleforipuvenuto.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/8ad2ec2670393a72611129f66fda680d/xegiwat.pdfIn PDF document text
    • http://kennyre.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135dbb24aadd---69254926774.pdfIn PDF document text
    • https://rhythmcprandfirstaid.com/wp-content/plugins/super-forms/uploads/php/files/c78994d875be1e776d4e8f5f1a7fcec1/30538685620.pdfIn PDF document text
    • http://htwy.com/upload/file/89242400687.pdfIn PDF document text
    • http://change4best.ru/upload/file/muzanepakasejopaperedu.pdfIn PDF document text
    • http://risme.vn/files/petedasefomajolu.pdfIn PDF document text
    • http://miryangpension.com/FileData/ckfinder/files/20210908_13C23A549579AA6F.pdfIn PDF document text
    • https://vnjhanoi.com/upload/files/53998466877.pdfIn PDF document text
    • https://srilangkapools.com/contents/files/tetonalaxakazetisujekub.pdfIn PDF document text
    • 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_off0000b526.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB526 18636 bytes
SHA-256: 0410949afc6980643df3b9005532f1107cca70f8880375b0a299dc1813940ca2
font_01_sfnt_off0000e446.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE446 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fc5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC5D 10772 bytes
SHA-256: 32d377387eaaaec32f42cd983126fb103ca2572115f7f62c0bb91b2879f95041