Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c5a8af4ea11cf7b…

MALICIOUS

PDF

91.0 KB Created: 2021-07-24 11:03:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: c7df9fb6c330c49caa895b8bb1a3a2b3 SHA-1: 3e582f9f22236505232c34d7d1ad7183036de574 SHA-256: 8c5a8af4ea11cf7bb0cf4e9e52e487f929f4acc7e1cbf7aae0a88cab68188429
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, pointing to numerous URLs hosted on compromised CMS uploads and disposable domains. The document body is heavily obfuscated and unreadable, suggesting it is designed to obscure its malicious intent rather than convey information.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://agribusiness.pk/wp-content/plugins/formcraft/file-upload/server/content/files/160c63d3f36ce9---gibanurulowamamosojoz.pdf In PDF document text
    • https://alcc.vn/wp-content/plugins/super-forms/uploads/php/files/pcq4pckpo11g6o3duh0opig3ul/vurotu.pdfIn PDF document text
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/160bfc820cee6d---7745882390.pdfIn PDF document text
    • http://brodart01.com/wp-content/plugins/super-forms/uploads/php/files/aja02srafuvphsifnmms4dgteg/mukodapele.pdfIn PDF document text
    • https://www.sacproblemleri.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bef763bd029---46816277174.pdfIn PDF document text
    • https://mountainbrookbuilders.com/home/mountain/public_html/ckfinder/userfiles/files/81091374684.pdfIn PDF document text
    • http://meandnetworking.com/ckfinder/userfiles/files/supepukegotejewafawivix.pdfIn PDF document text
    • http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/697073a1902752076621a430a05c19b8/fafujumuwog.pdfIn PDF document text
    • http://bobiniauto.com/userfiles/file/86517362633.pdfIn PDF document text
    • http://am-assets.com/aom/magnolia/userfiles/file/xiwife.pdfIn PDF document text
    • https://cffcommunications.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/160a0abd05af8b---viregit.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160e0278678790---23314110944.pdfIn PDF document text
    • https://iamluno.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a85d695b1d0---2042045500.pdfIn PDF document text
    • http://shinies.ru/img/lib/file/fititifonezulesulo.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160a76e4cea978---juzoximen.pdfIn PDF document text
    • http://gayaarchi.com/userfiles/file/20210717134914.pdfIn PDF document text
    • https://tekartltd.com/upload/files/28700138725.pdfIn PDF document text
    • http://ggmtc.net/userfiles/files/tixasekabiket.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083c19f394af---75960787016.pdfIn PDF document text
    • https://harpethvalleyhealth.com/wp-content/plugins/super-forms/uploads/php/files/c5d51a8ef24326bd9da6f426a5de3433/pafumuf.pdfIn PDF document text
    • http://www.videocopilot.net/assets/public/ckfinder/userfiles/files/niwadotuzonitiwolojomu.pdfIn PDF document text
    • https://warungmimpishio.com/contents//files/58482218759.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/ragujanexunezitewazoz.pdfIn PDF document text
    • http://tao123.me/pro_pic/files/42756200996.pdfIn PDF document text
    • http://aaaexpressheating.com/userfiles/file/fudadujusexisekivitijeju.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=ias+38+intangible+assets+questions+and+answers+pdfPDF 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_off0000febb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEBB 16728 bytes
SHA-256: 837a801926bf62e90d9c917218f23cde77a5daab7419cf1d1acf2860c417bff3
font_01_sfnt_off00012a5d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12A5D 11476 bytes
SHA-256: 34e373908be116839154f9b141b44932125874ee364b97ca8123309f9a4f2972
font_02_sfnt_off000144f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x144F9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1