Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac413e76911d866e…

MALICIOUS

PDF

79.9 KB Created: 2021-09-07 18:23:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 803ef48db2301d8ecbfc40144d285ba8 SHA-1: 6b936e49cfdc1d5a5ab73b853119d6f9aa8fdd14 SHA-256: ac413e76911d866e79b6edca2735306d2127e2d2b08372c984fd5c52d860b47d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to compromised WordPress sites and disposable domains, masquerading as a file converter or download. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to deliver a secondary payload or phish for credentials. No scripts were extracted, but the URL structure and heuristic firings point to a phishing or downloader attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://nomylo.ru/uplcv?utm_term=conversor+de+pdf+para+word+editavel+gratis PDF link annotation
    • https://digireg.li/upload/89098390912.pdfIn PDF document text
    • http://www.sg-callenberg.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2122226b1---fofepekod.pdfIn PDF document text
    • https://agenciaboom.com/wp-content/plugins/super-forms/uploads/php/files/ol9152lt78iulniqsutrjo0jq2/98568935180.pdfIn PDF document text
    • https://wholisticvibrations.com/wp-content/plugins/super-forms/uploads/php/files/bc882156a0e4ee4118c6850717e5f751/79841200386.pdfIn PDF document text
    • https://www.penyembuhanholistikreiki.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606d9e1a63123---subabufojekugob.pdfIn PDF document text
    • https://tallerescarrion.com/uploads/file/72578784766.pdfIn PDF document text
    • http://www.amanuttarakhand.org/ckfinder/userfiles/files/mejagabidilugizubeloxajun.pdfIn PDF document text
    • http://penzionriverside.cz/files/file/nadifenizijigerodumo.pdfIn PDF document text
    • https://sharzh-ufa.ru/wp-content/plugins/super-forms/uploads/php/files/c546c82353ba5c01c3191ed4dc7e0297/6665282302.pdfIn PDF document text
    • http://aihyang.com/userfiles/file/madewaxusoza.pdfIn PDF document text
    • https://satbietthu.com/luutru/files/lezinuzanuxosux.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c965d53d26b---dumas.pdfIn PDF document text
    • http://studiomontironi.eu/userfiles/files/57743406364.pdfIn PDF document text
    • http://videofilm-tv.ru/content/File/gexegapi.pdfIn PDF document text
    • http://dossalas.com/wp-content/plugins/super-forms/uploads/php/files/96c280576fd8d3f0240650761e3d5fb8/wumesunobejepurofuvuf.pdfIn PDF document text
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607d590f7aa85---12517097729.pdfIn PDF document text
    • https://jagamimpi.com/contents/files/2224469363.pdfIn PDF document text
    • https://keyseries.us/userfiles/file/nosiwonodorozenob.pdfIn PDF document text
    • http://vitalenzyme.com/uploads/fckupload/file/2091622877.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/16092a5aceaa81---xalovodofemevex.pdfIn PDF document text
    • http://fsoa.cn/userfiles/file/zodazemik.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e2e80caaba---taputularukafedijuwit.pdfIn PDF document text
    • https://www.unimedbelem.com.br/painel_template/assets/global/plugins/ckfinder/userfilesfiles/57855099635.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_off0000d2e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2E6 10856 bytes
SHA-256: 9aaa6ab2c4b196e6f9d9648809b7cdb222407ec820911f2e21142990cbbc17d9
font_01_sfnt_off0000ec05.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC05 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010417.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10417 17676 bytes
SHA-256: dc0a8072290e76c24ad757fb5f8376460856d672e442c9d1a03f8e6a3e603905