Malicious PDF — malware analysis report

Static analysis result for SHA-256 83f9075f92dbd89b…

MALICIOUS

PDF

83.2 KB Created: 2021-09-22 21:28:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: d2ac99885b84e5ebcaedcbc188b090a0 SHA-1: 50a205fd3a1830a1de69e41365e2f3e399d383c1 SHA-256: 83f9075f92dbd89b5981127b887ba5acb6e1873355bc3e6bb08ef6945308f569
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and numerous URLs, many of which point to compromised WordPress sites or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware delivery. The embedded JavaScript is likely used to obfuscate the malicious links or initiate further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://hoadondientu-ptp.vn/images/ckeditor/files/gopaniwegujikodotolabebop.pdf In PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130ed061dba9---vazumaxefigojagopux.pdfIn PDF document text
    • https://quanghuydulich.vn/img_duhoc/files/rajawonuju.pdfIn PDF document text
    • https://espritgt.com/userfiles/file/pawuniporavejetujatulir.pdfIn PDF document text
    • https://onthespothousing.com/userfiles/file/82250339148.pdfIn PDF document text
    • http://planet-for-events.de/userfiles/file/xotijirik.pdfIn PDF document text
    • https://yomadesign.com/userfiles/Proj_Name/files/kovagolumakonutiki.pdfIn PDF document text
    • http://glina-master.ru/admin/ckfinder/userfiles/files/batuxupiz.pdfIn PDF document text
    • https://markzone.az/wp-content/plugins/super-forms/uploads/php/files/f9s5elk4d094thbgp7hj7il0ov/wudenuzitelukek.pdfIn PDF document text
    • http://gartenmessebau.de/uploads/files/guboxujevumasan.pdfIn PDF document text
    • http://daieimotors.com/js/upload/files/95924141655.pdfIn PDF document text
    • http://phongkhamthienhoa.org/images/files/jusatovoxuwa.pdfIn PDF document text
    • http://ctcinsulator.com/uploads/file/7344388195.pdfIn PDF document text
    • http://profil-metall.de/content/uploads/file/sezakifov.pdfIn PDF document text
    • http://vivaibonomo.it/userfiles/files/tusebok.pdfIn PDF document text
    • https://newegys.egyseg.eu/ckfinder/userfiles/files/tobaxinafi.pdfIn PDF document text
    • http://szerecsen.hu/editor_up/90115999941.pdfIn PDF document text
    • https://kisikana.hr/UserFiles/files/nofapuniwemidubaladebez.pdfIn PDF document text
    • http://chinawin-consult.com/userfiles/10667162279.pdfIn PDF document text
    • http://matchonusa.com/uploads/files/jesajufuwonidijafimilufe.pdfIn PDF document text
    • https://journalofcritique.com/ckdosyalari/upload/files/96980917851.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16137dd7b3daa1---52585167957.pdfIn PDF document text
    • https://bistro-8.com/wp-content/plugins/super-forms/uploads/php/files/abf8752acc34b2749531bea16a671e08/safab.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=health+mate+apkPDF 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_off0000e361.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE361 10016 bytes
SHA-256: 4f4ea807f5679310db71aba6d463b1a43a93f51eff13e6547218be25d3ad9ddb
font_01_sfnt_off0000f98b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF98B 17792 bytes
SHA-256: e2705609efdf78d4546381dbced13f942a0359711309fc0ea5016339b11809f0
font_02_sfnt_off00012783.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12783 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1