Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c490b559cd5b329…

MALICIOUS

PDF

87.6 KB Created: 2021-06-26 07:04:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-25
MD5: c6315ae915d03ca371d7120f27b766ff SHA-1: b11a9ce07e440fb6452d270d6ba8b0dbd919f414 SHA-256: 4c490b559cd5b329f32ad19b57e8a0b2518a4b870337aee65d0ab2a8518b4cd6
96 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads and disposable hosting domains, indicating a link farm or redirection scheme. The ML classifier strongly flagged this PDF as malicious. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 5

  • 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://74ahs.com/clients/2/2a/2a132ee8da0778863662fd4b1fa251ed/File/pusubijuzilazujutudo.pdf In PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16099ce39b6863---zomafitar.pdfIn PDF document text
    • http://www.nowsingapore.co.id/wp-content/plugins/formcraft/file-upload/server/content/files/1606cc8762d5df---96267725818.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607567c56b902---4845168776.pdfIn PDF document text
    • https://deesudcoolingtower.com/userfiles/file/72483085418.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/1608517e811b16---rukixira.pdfIn PDF document text
    • http://zwickerfoto.hu/_user/file/83247526092.pdfIn PDF document text
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607c3814d8823---mubugunugikogasinopof.pdfIn PDF document text
    • https://forkidsvietnam.vn/wp-content/plugins/super-forms/uploads/php/files/ekv43bsgse785u20aqiob48iqv/78131556199.pdfIn PDF document text
    • http://asokmontridental.com/userfiles/file/71721335094.pdfIn PDF document text
    • https://apparel.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/311a0731b67f941c861356185d848083/96808632193.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1609262cce5361---19019732641.pdfIn PDF document text
    • https://realestateconnect.biz/wp-content/plugins/super-forms/uploads/php/files/m8e9cbr7c62vor15482i0ilc41/41487047749.pdfIn PDF document text
    • http://zulassung4you.de/bilder/file/gilunave.pdfIn PDF document text
    • http://bafiti.com/sklep/userfiles/file/4730672434.pdfIn PDF document text
    • http://nyett.hk/uploads/news/files/fufesimakafugo.pdfIn PDF document text
    • https://www.pharmaright.ca/wp-content/plugins/super-forms/uploads/php/files/hj052u4rbd8gbaih4qaii8j3mt/sewajatuxomovux.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b1ff2e27c4c---dufavifamiv.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/d24a971cff314bbeedc272dfc7a59ecf/surudosiwekusumexedini.pdfIn PDF document text
    • https://samyenngochoang.com/wp-content/plugins/super-forms/uploads/php/files/me3u271p2ngogh18nmer90342o/54086129947.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/upucj1kjlnrf5o2q3jvs8q3pjq/roruresigaloti.pdfIn PDF document text
    • http://www.kickcommerce.com/userfiles/file/98503145250.pdfIn PDF document text
    • https://iva-vietnam.com/userfiles/file/jagokimazeviraru.pdfIn PDF document text
    • http://sad-azov.ru/wp-content/plugins/super-forms/uploads/php/files/39d151c39ae91cab86079786aa15a94d/97617106867.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=birthday+wishes+in+gif+with+namePDF 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_off0000f11d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF11D 17844 bytes
SHA-256: bc93c77a63121e0525d2eed8c7163912a67a217e02421c77f433742491d95b7d
font_01_sfnt_off00012027.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12027 10888 bytes
SHA-256: a3f6d7f0b515ae5b0487d78b1625b58e5954df9740e78015d93ccdb327e71376
font_02_sfnt_off00013906.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13906 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1