Malicious PDF — malware analysis report

Static analysis result for SHA-256 d8a56c890934f864…

MALICIOUS

PDF

76.6 KB Created: 2021-09-18 09:33:12 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: c77461dcaac6df2f235e7cebb39ce43a SHA-1: e38486da9325d3a319e07440b54694c134b364c6 SHA-256: d8a56c890934f86422e568367a94e5ca42f0cda8e31e52104a833b2c3ab96712
164 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous URLs, many of which point to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The presence of embedded JavaScript indicates an attempt to execute code, likely for further exploitation or payload delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9827

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 https://inwebjor.ru/uplcv?utm_term=google+student+portal PDF link annotation
    • http://ministryofrum.com/memlogos/file/41628426587.pdfIn PDF document text
    • http://sungwoneng.com/upfile_editor/2021/files/81469453738.pdfIn PDF document text
    • https://bodymart.in/ckfinder/userfiles/files/gizesifemuzewagoposovige.pdfIn PDF document text
    • http://pastadimatteo.com/ckfinder/userfiles/files/78821113313.pdfIn PDF document text
    • https://centaur.vri.cz/docs/files/58530914540.pdfIn PDF document text
    • http://studioaba.net/userfiles/files/89036669618.pdfIn PDF document text
    • https://dascalita.ro/app/webroot/files/userfiles/files/lapokelanikawisikera.pdfIn PDF document text
    • http://pileki.com/imgup/file/10849876106.pdfIn PDF document text
    • http://grancanariacomercio.com/documentos/file/34883172142.pdfIn PDF document text
    • https://net-mex.hu/ckfinder/userfiles/files/mobekolejowafirefiludokid.pdfIn PDF document text
    • https://bem-sa.com/img/file/16235347259.pdfIn PDF document text
    • https://nucamsa.es/userfiles/files/gogolafu.pdfIn PDF document text
    • https://inmaabiladi.com/userfiles/files/bewego.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/161455626518aa---63728022008.pdfIn PDF document text
    • http://mediasingrid.com/js/new/fckeditor/userfiles/file/nudumusovuduwadakemudo.pdfIn PDF document text
    • https://coastalholidayproperty.com/ckfinder/userfiles/files/xatib.pdfIn PDF document text
    • http://ticketsperiodico.com/galeria/files/99780092956.pdfIn PDF document text
    • http://ckm-machinery.com/userfiles/files/94504308897.pdfIn PDF document text
    • http://ruresept.ru/files/file/37618591841.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/5f92365dc253384ade629af24cf1f804/36909316491.pdfIn PDF document text
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136580db051b---96519371208.pdfIn PDF document text
    • http://fese.in/ienupdimages/images/files/gepokagikikewuxesoni.pdfIn PDF document text
    • http://swaving-stalinrichting.nl/ckfinder/userfiles/files/foxijafigotiliwugipinoreg.pdfIn PDF document text
    • http://kraemer-duennebacke.de/files/file/ragaletegesunobulabon.pdfIn PDF document text
    • http://union.travel/ckfinder/userfiles/files/ripovimo.pdfIn PDF document text
    • http://lednotice.com/userData/board/file/41292466943.pdfIn PDF document text
    • https://estduquebec.com/scripts/php/xenocode/lib/ckfinder/userfiles/files/vovamiragimo.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_off0000ca1f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA1F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e236.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE236 10612 bytes
SHA-256: 21c3a6e0174388d4aeed0643cb16816d80372a42d3d5fef94f3c28152def1b1e
font_02_sfnt_off0000fa73.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA73 16496 bytes
SHA-256: df4c4701acf67e65ded177684c1f49ecf73a42b1b153345da74b89a75c871980