Malicious PDF — malware analysis report

Static analysis result for SHA-256 952d098bc45fcbfa…

MALICIOUS

PDF

81.2 KB Created: 2021-09-03 11:31:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 077bbc35fc4198514e286f77d5c165cb SHA-1: f214caf39fd986c1adb01184322d2a8c05895f42 SHA-256: 952d098bc45fcbfa050e06db84a23a810799f3329f15233565cd5e65d44f1725
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample is a PDF document identified as malicious by ML classifiers and ClamAV. It contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to distribute malicious content or phish users. The document body is heavily obfuscated and appears to be auto-generated content from wkhtmltopdf, lacking any discernible user-facing text.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://minhanh.com/files/84588998344.pdf In PDF document text
    • https://www.novet.de/wp-content/plugins/formcraft/file-upload/server/content/files/16072c1ef5737f---bowavufizagif.pdfIn PDF document text
    • http://yanartextil.com/firma/files/22928078462.pdfIn PDF document text
    • http://charivne.info/images/file/64311084724.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/a26e1f0d5a1a945227f6b688dbc4a519/27752935955.pdfIn PDF document text
    • http://abwbaltimore.com/uploads/files/63773547118.pdfIn PDF document text
    • https://tideandtigers.com/ckfinder/userfiles/files/48284736254.pdfIn PDF document text
    • http://industrialsupplies.pk/userfiles/files/sopiwexovaxeteratu.pdfIn PDF document text
    • http://nfrostov.ru/upload/files/kibozefatitati.pdfIn PDF document text
    • http://www.mostenpo.jp/userfiles/files/nanopalodetejexetom.pdfIn PDF document text
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/45277689034.pdfIn PDF document text
    • http://sushikyototogo.com/uploads/files/xemopabate.pdfIn PDF document text
    • https://www.adcgrain.com/wp-content/plugins/super-forms/uploads/php/files/fa95c193928915bb76f4a0d29fea5c06/zopuguled.pdfIn PDF document text
    • http://feast.to/upd_file/dujugezogutexumi.pdfIn PDF document text
    • http://indel.sk/userfiles/file/xuzixusubopelogofebevez.pdfIn PDF document text
    • https://www.lamuccacompany.com/wp-content/plugins/super-forms/uploads/php/files/5cd9abd55a444db49bedda35f43b56e7/37015278780.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c2d9558ba3b.pdfIn PDF document text
    • http://zpb-maciejewski.pl/upload/fck/file/63407523791.pdfIn PDF document text
    • http://diagonal.org.ar/wp-content/plugins/formcraft/file-upload/server/content/files/16103305046ad1---3490907146.pdfIn PDF document text
    • https://sieuviet.net/webroot/img/files/13053697601.pdfIn PDF document text
    • http://vitalchurchesinstitute.com/files/file/63186013885.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/54475145882.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/161094910407e3---telopinabebo.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=hormones+of+happiness+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_off0000d9c6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD9C6 17728 bytes
SHA-256: 491c935d85bfc6f17062615e9abc2465782f371c8d6e7fc491403b7dd33daf6a
font_01_sfnt_off00010762.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10762 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011f79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11F79 10608 bytes
SHA-256: ca7a4e261783d3d3d33599bdfab8c1982e616b86ff2982ca1caab8480b523156