Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1792c7bb9d4df5f…

MALICIOUS

PDF

82.9 KB Created: 2021-09-17 09:59:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 4b1efbdbd73740bdaac4056d968c9cad SHA-1: 83db28c0fcfafa0b8564fcef9765a9f05519649a SHA-256: d1792c7bb9d4df5fe5f3f6edc6d87397ed1d73954fe3f8f787fec4d76b03c50f
156 Risk Score

Malware Insights

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

The PDF file contains a link farm with numerous URLs pointing to compromised CMS upload directories and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The primary attack pattern involves luring users to these compromised sites via a malicious attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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 http://szpitalstrzelin.pl/userfiles/files/sowokeba.pdf In PDF document text
    • http://portalpr-b2b.es/img/user//file/_0916773001630964884.pdfIn PDF document text
    • https://ag-concept.ru/wp-content/plugins/super-forms/uploads/php/files/f0ae29e4f618c20e38e6c81a3ef0b2cc/62276712380.pdfIn PDF document text
    • http://thanhlamresort.vn/wp-content/plugins/formcraft/file-upload/server/content/files/16138a7895c5c8---6446412055.pdfIn PDF document text
    • http://evolutionchonburi.com/userfiles/files/76884610813.pdfIn PDF document text
    • http://yaqeen-eg.com/userfiles/file/84062040865.pdfIn PDF document text
    • http://angel-conference.org/upload_fck/file/2021-9-12/20210912175058154897.pdfIn PDF document text
    • https://goodnest.info/tctt/sites/aaa/file/vinorigasig.pdfIn PDF document text
    • https://mywayrtk.com/userfiles/file/23982495990.pdfIn PDF document text
    • http://gruppocinofilomarsalese.com/userfiles/files/junub.pdfIn PDF document text
    • http://spc1991.com/ckfinder/userfiles/files/sisudufixiwo.pdfIn PDF document text
    • https://shindah.com/images/ckeditor_img/files/48984036751.pdfIn PDF document text
    • http://euskararenginkana.eus/files/galeria/files/25646109433.pdfIn PDF document text
    • http://www.inhd.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613f915683771---89838386214.pdfIn PDF document text
    • https://bliznacite.dvsportbg.com/files/vubalerolafe.pdfIn PDF document text
    • https://majorsagilekvaros.hu/uploads/file/94518098804.pdfIn PDF document text
    • http://staceyasp.com/UserFiles/file/29737366745.pdfIn PDF document text
    • https://sierrainstruments.cn/fckeditor/editor/filemanager/connectors/php/fckeditor/upload/202109/file/16732504268.pdfIn PDF document text
    • https://yuvasarkar.org/userfiles/file/leniz.pdfIn PDF document text
    • http://himalayakebab.com/shipinc/userfiles/files/vurida.pdfIn PDF document text
    • http://kbcsisa.com/upload/fckeditor/file/kelekapojat.pdfIn PDF document text
    • http://vakantie-noordlimburg.nl/ckfinder/userfiles/files/kivubipiwiwewewetavebimo.pdfIn PDF document text
    • https://stealthwindow.tw/uploads/files/202109111901096058.pdfIn PDF document text
    • https://kientrucqhouse.com/uploads/image/files/poluwakexorosirekekudaw.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=apps+lagu+free+untuk+iphonePDF 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_off0000dd78.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD78 17584 bytes
SHA-256: 4ec4a8607c7486af6f08dc465977bdfe80bfc006518bc414ce266f10ab1e30e3
font_01_sfnt_off00010b62.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10B62 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00012379.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12379 10812 bytes
SHA-256: 6d0bc7c3b15b8b1076f2ccc0c75edfd6a46c871f01c052bc87a9b03a2f2bbc7a