Malicious PDF — malware analysis report

Static analysis result for SHA-256 8656181b43bb4807…

MALICIOUS

PDF

79.3 KB Created: 2021-08-14 22:37:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 9bbe5cbcc4ab5d7da46eee9fb337a5e2 SHA-1: 2f0e6ff6fae2c765473a21342bb3609bc5f264d0 SHA-256: 8656181b43bb4807ae324bca8e773e0c510cb03d150f36aa62e2f095d6deb891
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as link farms. The ML classifier strongly indicates maliciousness, and the heuristic firings suggest the document is designed to redirect users to potentially harmful content or exploit kits. No scripts were extracted, limiting the analysis of direct execution capabilities.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9958

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://relaxationplusmn.com/wp-content/plugins/super-forms/uploads/php/files/684355f347cbf992184c389d914b5d09/30793738248.pdf In PDF document text
    • http://neboskreb-irk.ru/uploads/userfiles/files/werotoxarulozogewalo.pdfIn PDF document text
    • https://sahodayabbsr.com/test/fckeditor/file/letosanufelejifopefumu.pdfIn PDF document text
    • http://www.barankayalar.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160949b4da5da3---jimegulow.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/28768693442.pdfIn PDF document text
    • https://allmassage.net/upload/file/20210617151723.pdfIn PDF document text
    • https://cms.blauraum.com/wp-content/plugins/super-forms/uploads/php/files/8cabdb524e0cdead395b3f1a1dae91cf/fizapufibufirixa.pdfIn PDF document text
    • http://autobedrijvenindex.nl/images/uploads/8040875243.pdfIn PDF document text
    • http://k-yoga.org/file_upload/spaw_upload/file/20210602172223.pdfIn PDF document text
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160f375054bd86---nulugota.pdfIn PDF document text
    • http://www.julitolaschools.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609ba692addf6---14342402688.pdfIn PDF document text
    • http://2girlstrippin.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ffe7ee5d8ed---44511105444.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a6b82cd8e25---kubevigixudapewu.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/e288ff5dc63840e15a3c7615a000e878/masanoxi.pdfIn PDF document text
    • http://zuche0551.com/upload/file/buvosusefuwope.pdfIn PDF document text
    • http://houselandia.ru/files/34154478709.pdfIn PDF document text
    • http://theopenhouseclub.com/wp-content/plugins/super-forms/uploads/php/files/5f9ccdbb8764045a9984164b78ba4c4b/lojasisoruwok.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/cb776237f1c23918e05005f7d9f04da3/dakupinixutuke.pdfIn PDF document text
    • https://www.inkfactory.pk/wp-content/plugins/formcraft/file-upload/server/content/files/1607ab5b40b49f---53498893995.pdfIn PDF document text
    • https://zifu-tech.com/app/webroot/userfiles/files/kasejawo.pdfIn PDF document text
    • http://escolacaritas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16091146b45818---62189443182.pdfIn PDF document text
    • https://www.toptalentusa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e25aa38e720---48462667890.pdfIn PDF document text
    • http://blossomtour.net/FileData/ckfinder/files/20210709_981BA3732079518B.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=fl+studio+20+dholki+pack+zip+free+downloadPDF 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_off0000cda8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCDA8 18056 bytes
SHA-256: e90d071e9d4bc07d0e7e18cd48070510e181d4c4f404fdbf57caff34be891857
font_01_sfnt_off0000fd0c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD0C 11272 bytes
SHA-256: f3e5bec9e31b7f57cf6807e7a56b8cc20bfbf25108ce92a4ff45fb5600bd4c2c
font_02_sfnt_off0001179e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1179E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1