Malicious PDF — malware analysis report

Static analysis result for SHA-256 6a40ba0a2b2b549a…

MALICIOUS

PDF

91.7 KB Created: 2021-06-27 14:41:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 562fd383d9b9f24bff6615c13273e942 SHA-1: 7721ccfc5aee1ea272c9531519efc9935e25de1a SHA-256: 6a40ba0a2b2b549a79cf1c09a09b25b5ef2fdd05c39bf13ddb2bea53530fc6dc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links, many pointing to other PDF files hosted on compromised websites, indicating a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://www.dnevi-sekretarjev.eu/wp-content/plugins/formcraft/file-upload/server/content/files/160a03a070e916---ruwuwaribavumetozawiw.pdf
    • https://patriot.ch/wp-content/plugins/super-forms/uploads/php/files/cv45mvdgp0eidea58jbud4bkjr/39470947041.pdf
    • https://divorcioconsensual.com.br/wp-content/plugins/super-forms/uploads/php/files/7600487b4ee87126aa06144aef24df05/60390081745.pdf
    • http://azizolace.cz/images/file/16770876941.pdf
    • http://www.socalgreatwhite.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606fedaa25ca6---78818687672.pdf
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/b81b8cc03ab457e5b48534e99791191a/33602368771.pdf
    • https://alves.bg/ckfinder/userfiles/files/17600971136.pdf
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d83284caa04---kagufoleset.pdf
    • http://southfieldhigh1973.com/clients/2/27/27a5067865c8334ad4a5a1fd7642c928/File/sanujejavetagidopex.pdf
    • http://blackivy.pl/userfiles/file/lekuwu.pdf
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1609be42875c95---jomegilagisakijomakuro.pdf
    • http://midlandhigh65.com/clients/6/68/682e31fde28f8c6bff7ebba57332ef5f/File/bugujavanarutiwogigoxudik.pdf
    • http://mwflower.com/upimagesfile///zeterajajepavidenom.pdf
    • http://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad9f5c477f0---duselu.pdf
    • http://www.gainerwindows.ca/wp-content/plugins/super-forms/uploads/php/files/7vv12sd6dtmjqqu7v5roitoqr0/pilararitevokow.pdf
    • https://www.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c037529421d---piwirixizomatufiloj.pdf
    • https://twr1115.net/files/fckeditor/file/26899526979.pdf
    • https://mps-india.com/userfiles/files/vokugevebaxupe.pdf
    • http://interwork.sk/userfiles/file/xavelar.pdf
    • https://lakeshoresmilesdentistry.com/wp-content/plugins/super-forms/uploads/php/files/id5c225q6l6j8kq02tbjnchuu3/xunemuwuxonifosizobufu.pdf
    • https://www.abaco-engineering.it/wp-content/plugins/formcraft/file-upload/server/content/files/160a96451dd040---mibom.pdf
    • https://engineeredrepinc.com/wp-content/plugins/super-forms/uploads/php/files/bf50c211d5b361e13cf07a172cb2ff6a/tamulakivawo.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=baked+scrambled+egg+cups
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000102f2.bin
15bba360ac5af802f927dfe502a220aa04abd316cfb9d610f982ddd5a96623c0
pdf-font-stream PDF embedded font (sfnt) at offset 0x102F2 10828 bytes
font_01_sfnt_off00011b8a.bin
c5c647ae8a4495ac66da9d815abd82de6c10de939fd3f4545894755914ea3fc1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B8A 17944 bytes
font_02_sfnt_off000149a3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x149A3 16792 bytes