Malicious PDF — malware analysis report

Static analysis result for SHA-256 c11fa18f8b1e9526…

MALICIOUS

PDF

84.1 KB Created: 2021-09-02 06:45:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 5d8a366ec785b462a7472b318958fa35 SHA-1: ea1c0c9726d0c0a69c9558148e5e7dbad874ed13 SHA-256: c11fa18f8b1e9526dcdc60262d6a95ccde1e93a3395043123d1656ac754ae2c8
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was flagged by multiple heuristics as malicious, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. Numerous external URLs were extracted, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users. The ML classifier also strongly indicated maliciousness.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 https://crysiq.ru/uplcv?utm_term=watch+badhai+ho+online+free PDF link annotation
    • http://ecovn.vn/uploads/news_file/mavowikaxefi.pdfIn PDF document text
    • http://dobraukraina.org/sites/all/sites/dobraukraina.org/files/16652057578.pdfIn PDF document text
    • http://falconfam.com/ckfinder/userfiles/files/28132213187.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ab5f7388a2e---73808991302.pdfIn PDF document text
    • http://gtshotel.it/images/file/16020057080.pdfIn PDF document text
    • https://www.ikedatosou.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b804e677435---22999922841.pdfIn PDF document text
    • http://www.webtony.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160bccf2b82050---majigobef.pdfIn PDF document text
    • https://personalloan2u.com/wp-content/plugins/super-forms/uploads/php/files/d032b07ea2b9741b8a491816a8685822/zebepu.pdfIn PDF document text
    • https://apteka-wratislavia.pl/halatecza/userfiles/file/xetiranavagutuzamebab.pdfIn PDF document text
    • https://perleyparish.org/wp-content/plugins/super-forms/uploads/php/files/f2e35e857205320b0fcf830b70585ca1/82949005922.pdfIn PDF document text
    • http://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160b8b81040d22---69660053445.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607383ada3abf---29369942239.pdfIn PDF document text
    • https://www.scilights.com/wp-content/plugins/super-forms/uploads/php/files/51178821f6afafdfae7ad1f926f35c42/nojofupatokowaweseduxeza.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612d7384afe15---11791081326.pdfIn PDF document text
    • http://giadinhlaurenso.org/upload/files/84858996000.pdfIn PDF document text
    • http://greenplanetnepal.com/userfiles/file/kosisajipufajilesifo.pdfIn PDF document text
    • https://smobiil.eu/userfiles/files/jewigisolu.pdfIn PDF document text
    • http://bestorkate.com/uploads/ckeditor/files/zajogizeka.pdfIn PDF document text
    • http://intrinhgia.com/admin/webroot/upload/image/files/ruvuzugojeletatemupa.pdfIn PDF document text
    • https://hightechrustremovers.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160b7b8ffda7bf---41780058174.pdfIn PDF document text
    • http://www.canadavisaservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608d3833b25d7---33392097029.pdfIn PDF document text
    • http://theydeserveastamp.org/wp-content/plugins/formcraft/file-upload/server/content/files/16080ae726b239---20608653078.pdfIn PDF document text
    • http://stomerijindex.nl/images/uploads/xujozekegudir.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_off0000e357.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE357 17844 bytes
SHA-256: a2c420458324f46377f91c8731d6b725c4073f06c16e17bd23c09e0767d48645
font_01_sfnt_off00011177.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11177 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001298e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1298E 10540 bytes
SHA-256: 6b97d61874a03cd2125159dc933ac3224c625df716ffc3adc9de51a400785ade