Malicious PDF — malware analysis report

Static analysis result for SHA-256 f6521e24e520188b…

MALICIOUS

PDF

87.3 KB Created: 2021-06-21 17:43:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-29
MD5: a620c8489b5f939c64bb666e4ed1d9c2 SHA-1: a663d6e180be3f7a7495ccec946ea1707b3b340e SHA-256: f6521e24e520188b65e345bb45905432de472be9125d6abfa6c9564d7ffe6d8e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF contains numerous links pointing to compromised WordPress sites and disposable hosting, masquerading as academic papers to entice downloads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely to deliver a secondary payload. No scripts were extracted, but the link farm structure and heuristic firings suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://roocenter.ru/upload/file/15685835919.pdf In PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/6d11b5ec18bdd3a490fa7e278782e512/7723334869.pdfIn PDF document text
    • http://localhomesales.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160ada58f75428---15177846352.pdfIn PDF document text
    • http://bong-dem-long.org/upload/editor/files/96339678980.pdfIn PDF document text
    • https://segurosjdd.com/wp-content/plugins/super-forms/uploads/php/files/7h13a56uki2sk3qlkcqqapr4g5/xoritakum.pdfIn PDF document text
    • http://letsbelegal.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/89011212701.pdfIn PDF document text
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160c5880dcdc33---4161282900.pdfIn PDF document text
    • https://www.cedicar.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bf8730c0fcd---vigutepatazawolutuvozumud.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/16084daf253c87---zapevoxorifudemujefet.pdfIn PDF document text
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ae216f0b33---fufamofuwofozaxipurobijox.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1607e6f05732fb---4026443261.pdfIn PDF document text
    • http://birons.net/wp-content/plugins/super-forms/uploads/php/files/8ad00eab326d845bbba4522e0d026bbd/38695572174.pdfIn PDF document text
    • https://alianzatours.com/imagenes/file/52070086109.pdfIn PDF document text
    • http://xn--9p4b29dncp2cc6y.net/upload/fckeditor/file/68226333421.pdfIn PDF document text
    • http://gleneaglehoa.org/images/file/kogesazerezirajefomunasuz.pdfIn PDF document text
    • https://velvetskin.pl/wp-content/plugins/super-forms/uploads/php/files/f9fd6dd6ff0d184080ff9bfb4096f45f/filojovewozawagop.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/1xuhb7AK25c/uplcv?utm_term=psi+old+question+papers+in+kannadaPDF 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://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010e01.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E01 5144 bytes
SHA-256: 01805f6dd54cb749eac3d27a4a77b591cf9d632efe8bd1be06ec900e9998b0fe
font_01_sfnt_off00011f89.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F89 15400 bytes
SHA-256: 8a222db7a9eb127da0477b12aa9d739c645ab64adcbe4e89532279b8190c3654