Malicious PDF — malware analysis report

Static analysis result for SHA-256 174b9e27835b5172…

MALICIOUS

PDF

81.5 KB Created: 2021-08-29 17:05:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 596e833b9841ffa7bf2695841f77ca3b SHA-1: 925d57e41a7e0b02df267993d4d11f9db67c2ef7 SHA-256: 174b9e27835b51723328419b68ac5a090c4565b7757a24a1cfcb205f5a6074a1
96 Risk Score

Malware Insights

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

The PDF file contains a link farm pointing to numerous compromised websites, many of which are hosted on disposable domains. This suggests a tactic to manipulate search engine results or distribute malicious content. The ML classifier strongly indicated maliciousness, and the heuristic firings confirm the presence of a link farm on compromised CMS uploads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://www.higher-energy-trampolineclub.com/wp-content/plugins/formcraft/file-upload/server/content/files/16104721b5d619---10491940250.pdf In PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/7799fd95f6d7a2c8b55aa36e749d9953/sobiromituvesafovore.pdfIn PDF document text
    • https://www.kiteschule-kiel.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607a9c23d0f39---60986540095.pdfIn PDF document text
    • https://pasarangroup1.com/contents//files/xatawexoparisexa.pdfIn PDF document text
    • http://ahdjcm.com/upload/files/77170872312.pdfIn PDF document text
    • https://garnizone.com/userfiles/file/45649997239.pdfIn PDF document text
    • http://esistore.de/userfiles/file/katubudovabaj.pdfIn PDF document text
    • http://goldenbaycruisesagent.com/userfiles/file/57294676035.pdfIn PDF document text
    • https://adsbudget.net/userfiles/file/91576399627.pdfIn PDF document text
    • https://master.plus/wp-content/plugins/super-forms/uploads/php/files/660572eb88870491f226e79b584ac9f4/39053706278.pdfIn PDF document text
    • http://norilskgu.ru/userfiles/file/9939623292.pdfIn PDF document text
    • http://elite-nails.pl/Upload/file/83291205731.pdfIn PDF document text
    • http://winso.tw/userfiles/file/relinidovafuxazavifegiret.pdfIn PDF document text
    • https://tselectromechanical.com/uploads/CKfiles/files/73494242347.pdfIn PDF document text
    • http://gldbirdgel.com/user_img/files/xadibolijovu.pdfIn PDF document text
    • https://mangonebike.com/uploads/file/katekerekiranevoworalage.pdfIn PDF document text
    • http://tuanlongland.com/upload/files/79763858804.pdfIn PDF document text
    • http://klassn.com/ckfinder/userfiles/files/nakapewu.pdfIn PDF document text
    • http://indiebookoftheday.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611edc8e23271---33911413911.pdfIn PDF document text
    • https://profbuhotchet.ru/wp-content/plugins/super-forms/uploads/php/files/2e9f30be41187290b992956121406c5e/13926830759.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/4c00498a4f64add8f8313a7f51531895/kamob.pdfIn PDF document text
    • https://mundolibre.cl/uploads/userfiles/files/fumepimewow.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/50066528416.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=synthesis+of+nanoparticles+by+ball+milling+method+pdfPDF 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_off0000d82e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD82E 17356 bytes
SHA-256: 31e3ba2219f0ca8280c34fe85da8f045232bd245f7a2ba6cb5cf895c30166b2f
font_01_sfnt_off00010512.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10512 11396 bytes
SHA-256: c962edfb2a3a6178d2b9419a447dbbe812ba3743728bd2425bff3a8bd209a8c1
font_02_sfnt_off00011f5a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F5A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1