Malicious PDF — malware analysis report

Static analysis result for SHA-256 805d3d3ca5cf2739…

MALICIOUS

PDF

69.0 KB Created: 2021-09-23 12:31:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 8fdfd5f656d79a2d95168419fde422f1 SHA-1: af6a242e96b541b451486756dd93b0fb601ef453 SHA-256: 805d3d3ca5cf2739adc0619c385642970cb36fbd934f483c25a27f0f2b90e538
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which are part of a link farm hosted on disposable or compromised domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and unreadable, providing no direct textual clues, but the heuristic firings and URL analysis are sufficient to determine the attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://huntic.ru/uplcv?utm_term=file+transfer+apps+for+android PDF link annotation
    • http://cancunday.com/travela/img/files/terarorogafo.pdfIn PDF document text
    • https://threadworx.com/thread/admin/uploads/file/42176912093.pdfIn PDF document text
    • http://tcsklife.com/filespath/files/20210910121915.pdfIn PDF document text
    • http://seto.cz/uploads/wofisexabibunefajipox.pdfIn PDF document text
    • http://audiohrestomatiya.ru/content/file/97797752769.pdfIn PDF document text
    • http://yushendesign.com/images_fck/file/1631359105.pdfIn PDF document text
    • http://guojingmall.com/userfiles/file///xexapatagenosit.pdfIn PDF document text
    • http://kalmi.ru/upfiles/files/wojawoxubosejazud.pdfIn PDF document text
    • http://alexandersorokolaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/salepomareje.pdfIn PDF document text
    • https://luxartparquet.com/wp-content/plugins/super-forms/uploads/php/files/5e0519e68acf21d5f834c6f822e93a5a/sedutusatapekuk.pdfIn PDF document text
    • https://srmhomes.com/images/bulk_images/files/70549361598.pdfIn PDF document text
    • http://zhouzhuank.com/v15/Upload/file/2021910826366520.pdfIn PDF document text
    • http://www.dr.schure.net/ckfinder/userfiles/files/94126016907.pdfIn PDF document text
    • https://myclubowners.com/userfiles/files/selekikewa.pdfIn PDF document text
    • http://didongsinhvien.com/upload/files/83049185213.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/06p5oat4b7trafi7d7hmd3bh8b/9092553754.pdfIn PDF document text
    • https://www.champagne-cornevin.fr/ckfinder/userfiles/files/kuromoxonirawojus.pdfIn PDF document text
    • http://foto-klub.dk/userfiles/file/kokatovexobafajixi.pdfIn PDF document text
    • http://4chan.ro/UserFiles/file/naninarakog.pdfIn PDF document text
    • https://michaels-limo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613dfcd466946---wokipifapebaxasixuw.pdfIn PDF document text
    • http://urduhadith.org/survey/userfiles/files/vigunofapukanewadiwin.pdfIn PDF document text
    • http://dogomanhnghia.com/uploads/files/94275937274.pdfIn PDF document text
    • https://www.champagne-auge-dascier.com/ckfinder/userfiles/files/56884828588.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_off0000b1ad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1AD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c9bf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9BF 14760 bytes
SHA-256: e590b8276eeb136f610b5cb1066616cc1f5ad9a43d0f5af71981cf23d66e595b
font_02_sfnt_off0000ee97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE97 10468 bytes
SHA-256: c21cc61bd4b4b370f64e5373e557734e9bf37d21cf76a850481a54c5be75cea2