Malicious PDF — malware analysis report

Static analysis result for SHA-256 7c3a73e192851a8c…

MALICIOUS

PDF

80.3 KB Created: 2021-09-19 12:05:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: cbf4f8e18dd05d5fd0f0194baa89ee68 SHA-1: 9f3ac229261bd0b44c7a870cfc52e2b626dd7118 SHA-256: 7c3a73e192851a8cbde8ec334a5a8341bd5e2bcdc4c1cb0c37c29fd85518a606
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous external URIs, many of which point to compromised or disposable hosting. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a pattern of using such links, suggesting an attempt to redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://stellarp.com/userfiles/files/37226789191.pdf In PDF document text
    • http://yuanyoujie.vip/userfiles/file/kifesiba.pdfIn PDF document text
    • http://loveperfectionschool.com/upload/file/xarixuvegodiledowelezu.pdfIn PDF document text
    • http://geombiagioschettino.eu/userfiles/files/20862933809.pdfIn PDF document text
    • https://supermagnum-bg.com/ckfinder/userfiles/files/96458553132.pdfIn PDF document text
    • http://ymy-tea.tw/upload/files/80979269771.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141e380d02a2---wivamiwutut.pdfIn PDF document text
    • http://bamila.vn/luutru/files/15214147599.pdfIn PDF document text
    • http://okuninka-biale.pl/userfiles/file/61104254039.pdfIn PDF document text
    • https://partetesal.ir/data/file/fubobuxolaluwotaze.pdfIn PDF document text
    • https://concertwristband.com/resimler/files/28342399075.pdfIn PDF document text
    • https://webaprint.be/img/file/ratutomibenomap.pdfIn PDF document text
    • http://stroykap.com/application/views/stroykap/userfiles/file/56081219502.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/3ac9b6e724c56565d27beb401f56eb5a/59167970133.pdfIn PDF document text
    • https://zevkotodoseme.com/upload/ckfinder/files/wavarepedegimuzofuluguj.pdfIn PDF document text
    • https://jocafoto.com/fotos/file/33040438739.pdfIn PDF document text
    • https://hbphoto.ca/resimler/files/13518252273.pdfIn PDF document text
    • https://basalyemek.com/ckfinder/userfiles/files/8356534075.pdfIn PDF document text
    • http://classiccar-jp.com/js/upload/files/nedoxonuxorigim.pdfIn PDF document text
    • http://faradbox.pl/files/file/kusawojul.pdfIn PDF document text
    • http://vhshf.de/File/bimimixasujanawiguzide.pdfIn PDF document text
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/16142cc344422e---88819808626.pdfIn PDF document text
    • http://taiwan-tsai.com/upload/files/17091383391.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3vuEKuznOb8/uplcv?utm_term=show+dialog+box+in+androidPDF 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_off0000d41f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD41F 18340 bytes
SHA-256: 188b83dc7aad1e2916ef6dbf17c7ec0e36b38ddfd2c46df8dfbed92d2d168978
font_01_sfnt_off0001043f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1043F 10532 bytes
SHA-256: ea3333d2b2bc9009af8d251442a87716f36216500ca781456facabe45745e882
font_02_sfnt_off00011bfb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BFB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1