Malicious PDF — malware analysis report

Static analysis result for SHA-256 41ca23bcf387cad4…

MALICIOUS

PDF

87.9 KB Created: 2021-07-05 07:04:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: fe60dd14ada51bfea73b78087091a4a4 SHA-1: ac9d18d2be940c303406a9c2ed41bf2e7b75f387 SHA-256: 41ca23bcf387cad4c5a4755e189714a5807d6b3f86efbde6f8fca955e2155958
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a malicious PDF detected by ClamAV and an ML classifier, containing embedded JavaScript. It functions as a link farm, directing users to multiple compromised WordPress sites and disposable hosting domains, likely for phishing or malware distribution. The presence of embedded JavaScript suggests an attempt to execute code within the PDF viewer.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://nomylo.ru/uplcv?utm_term=matching+activities+for+toddlers+pdf PDF link annotation
    • https://www.cr-sdc.org/wp-content/plugins/super-forms/uploads/php/files/729b66c57f8f214754d1f8caae996386/94287775326.pdfIn PDF document text
    • https://bangvetthuong.com/luutru/files/sijadubudasudopumapaxarez.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1606c6c3976a96---84770105877.pdfIn PDF document text
    • http://grandrosso.com/js/upload/files/selatirefavojetato.pdfIn PDF document text
    • https://jackyrouxmethode.com/userfiles/file/48216927309.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/160af28db53f63---9554460676.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ac8841b6389---lixakewe.pdfIn PDF document text
    • http://www.reenactmentmarket.eu/images/wyswig_images/file/bokozetegekazotameruw.pdfIn PDF document text
    • https://xehowo24h.com/images/ckeditor/files/65388702818.pdfIn PDF document text
    • https://ayurvedaemart.com/uploads/file/93360652392.pdfIn PDF document text
    • http://homeopathyhongkong.org/files/volivexudadetupakexajazep.pdfIn PDF document text
    • https://georgiamusicpartners.org/wp-content/plugins/super-forms/uploads/php/files/8b1e85b1bd8fc362c3f8a143262291ba/jusakasewixusuxojofarer.pdfIn PDF document text
    • https://la-klamm.org/userfiles/file/77713784827.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16071ae3b8dff2---20281106380.pdfIn PDF document text
    • http://canxetaianhduc.com/images/file/bujobesozaneku.pdfIn PDF document text
    • https://www.numberoneporthill.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160830b3ccd716---kutoraladogozisedoz.pdfIn PDF document text
    • https://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160abc51873fee---xovefetizununenimoloxowu.pdfIn PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608a80b05e379---57685383879.pdfIn PDF document text
    • https://etcbt.com/userfiles/file/befofijoxiv.pdfIn PDF document text
    • https://aryaayur.com/wp-content/plugins/formcraft/file-upload/server/content/files/160753bda152f6---18584717752.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608324a2d77f5---pawowojubenisugedu.pdfIn PDF document text
    • https://cullinanconstruction.com/wp-content/plugins/super-forms/uploads/php/files/cpra54n3b576cf16is80v4pgbk/52844446506.pdfIn PDF document text
    • http://softwarefactory.nl/images/file/zisojoli.pdfIn PDF document text
    • https://staffxrecruitment.com/wp-content/plugins/super-forms/uploads/php/files/f61a9fe2e1e6b82aa8b05cba03ea6cdb/70166134120.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_off0000f2f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2F8 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010b0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B0F 10956 bytes
SHA-256: da90c7a43b3d021e88e04f904a5a13e7d67ee0751dc779c61f1ba16798d04383
font_02_sfnt_off00012443.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12443 16984 bytes
SHA-256: dea3ef6292834d15759254a2d84d58487f31da69e7e5d621f2c839aac2b45e47