Malicious PDF — malware analysis report

Static analysis result for SHA-256 2acdfdacf80930cd…

MALICIOUS

PDF

102.5 KB Created: 2021-05-10 21:52:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 0c63266b2b59c6c11eaa04ae326549e1 SHA-1: 26d14a9bbda1a02a272597055b58f3f85dfc01bc SHA-256: 2acdfdacf80930cd986dfc7b989d99b8530211e80b36ffeccd21ec320258b7bd
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically identified as a phishing trojan. Analysis reveals it functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting. The document body, though heavily obfuscated, contains metadata suggesting it was generated by wkhtmltopdf, and the presence of multiple external URIs indicates an attempt to redirect the user to external content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • 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://agrilaui.com/userfiles/file/vawezesenarejo.pdf In PDF document text
    • http://heilpraxis-pankow.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607df53008e73---dusaxopevojevagunok.pdfIn PDF document text
    • https://ancoraeducacion.com/images/bulerikadufik.pdfIn PDF document text
    • https://www.histoiresdegroupes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160702cc78c14f---tofabawixebekifivesodusur.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/160876646cb92d---8295582409.pdfIn PDF document text
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/22477445fdcb2bcb1c70c5d9a00fc5cc/32563345461.pdfIn PDF document text
    • https://anmoul.com/userfiles/file/85827522062.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607caef708365---65131713473.pdfIn PDF document text
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/1608dd5f32e477---8649235731.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/51871b77aab64faa6bbca84eaf215cbd/bobimemenedop.pdfIn PDF document text
    • http://www.drop-lok.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080dea01f8e7---70835812438.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/d6c1a7bf1cadff1b83f7aa34925e32af/wuzodoro.pdfIn PDF document text
    • http://dirabrealtors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077641b9b7c0---kekirozebepulotopuzofu.pdfIn PDF document text
    • http://redwoodpwr.com/wp-content/plugins/super-forms/uploads/php/files/gm20nv35l2uk1lim0h606hpqi7/rafogagemipezixiginu.pdfIn PDF document text
    • https://smoothnomad.com/wp-content/plugins/super-forms/uploads/php/files/seu3q3731nfc8eqgh7vke6s06l/69979564871.pdfIn PDF document text
    • https://capitaleny.com/wp-content/plugins/super-forms/uploads/php/files/5c6f60a9ae6e3f9e9503c0ba68f6743b/95276941149.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=jsc+marksheet+with+number+2018+chittagong+boardPDF 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://scripts.sil.org/OFLIn PDF document text
    • http://www.geocities.com/mitra_anirban/hobbies.htmGNUIn PDF document text
    • http://www.gnu.org/copyleft/gpl.htmRegularIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00013e83.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E83 6124 bytes
SHA-256: 86a297dbbc1d8682c3bbfd30cdee7bd3486840344d7624a0995f255c87a9ba15
font_01_sfnt_off00015338.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15338 6108 bytes
SHA-256: ea4f7caf7798dd8cc00b4f6d0960fa9e5341cd938e2030185db47665ae73e7e7
font_02_sfnt_off0001673b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1673B 10992 bytes
SHA-256: b45b1b7ca714f495d007cde76613390e4f3577a1cc9ad5bdbfbffb194beebd0a