Malicious PDF — malware analysis report

Static analysis result for SHA-256 b9d73b51adca23d1…

MALICIOUS

PDF

88.7 KB Created: 2021-07-01 14:55:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: ad3f58f7f9018e4f35db6cd0ee28aa9a SHA-1: e0d1dab3065fb9a93d8b1dc23a5694181c96ee5a SHA-256: b9d73b51adca23d186e0128783081d3c9f0b3d6381dd5ddc6e0870aeeac42737
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics as malicious, including a high-confidence ML classification and ClamAV detection as a phishing trojan. It functions as a link farm, directing users to numerous compromised CMS upload locations and disposable hosting sites, likely to distribute further malware or conduct phishing attacks. The presence of embedded URLs and the nature of the link farm suggest an attempt to exploit users through deceptive links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • 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.
  • 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://qqhanoman.com/contents//files/gureni.pdf In PDF document text
    • http://www.auditsi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a34493d6750---96352220664.pdfIn PDF document text
    • http://starwindows.ie/ckfinder/userfiles/files/weziruwu.pdfIn PDF document text
    • http://www.thebetterinsurance.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608768bc69225---nagiwakobusa.pdfIn PDF document text
    • https://apz-arte.com/ckfinder/userfiles/files/jidesov.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/e2f407cff839dd40fce387f1c0e3d2dc/mabupevezok.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/3321a61cc6798d4c5c1eade23555c375/35732156532.pdfIn PDF document text
    • http://atomleasing.ru/media/File/kunivetiwiguxarupe.pdfIn PDF document text
    • https://cafesca.net/ckfinder/userfiles/files/20641341446.pdfIn PDF document text
    • http://www.carolglassman.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3694208c89---pebapagotodomo.pdfIn PDF document text
    • https://www.truegridpaver.com/wp-content/plugins/super-forms/uploads/php/files/403caee88a697bafd2922bf52d9b536c/55547354769.pdfIn PDF document text
    • http://china-zub.ru/userfiles/file/nulikojogoparurar.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/g0aem5t3hb7hfatb55cggfdun1/rajazelurababuvapif.pdfIn PDF document text
    • https://www.kalirich.com/wp-content/plugins/super-forms/uploads/php/files/dgvg2bodisdn6c3h13v68ii861/44241745171.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160a4bca126df7---11101824062.pdfIn PDF document text
    • https://xenang-mitsubishi.com/fckupload/file/2579845075.pdfIn PDF document text
    • http://absolutelyneon.com/userfiles/file/nuvix.pdfIn PDF document text
    • https://boumqueur-edition.com/upload/fckeditor/file/wolikuxafotapapusasoburaw.pdfIn PDF document text
    • https://seroinstitute.com/wp-content/plugins/super-forms/uploads/php/files/370b89202d78c6f930c38d40dd333aa3/furedagi.pdfIn PDF document text
    • https://praward.tw/wp-content/plugins/super-forms/uploads/php/files/19280666e0e4ad6f8a1281c6552cafcd/1766249292.pdfIn PDF document text
    • https://medgarlci.com/wp-content/plugins/super-forms/uploads/php/files/a2a0f7df4c0b643296dba640922538d8/83333016203.pdfIn PDF document text
    • https://avigailpekelman.com/sites/default/files/file/sukejel.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/16073b71fe05c0---bereva.pdfIn PDF document text
    • https://www.cdscabling.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606cad2c6244d---94914044070.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=4th+class+exam+paperPDF 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_off0000f79d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF79D 18108 bytes
SHA-256: be46ef64e67e46fdc2110625dc7eaf21cf3164e2f1100b34ec21415d82e33b9a
font_01_sfnt_off00012639.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12639 10408 bytes
SHA-256: 3c19e7e60b9cd5479cc16f6902eaaada24968e6b70736a38f219dfce6b5901fe
font_02_sfnt_off00013dd6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13DD6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1