Malicious PDF — malware analysis report

Static analysis result for SHA-256 f79c81ba54e916bd…

MALICIOUS

PDF

70.4 KB Created: 2021-09-13 00:07:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 9512cfe51e01f0ba10bbcea0446242d3 SHA-1: 2bc57421beb748d541adab527f7f1a77903462da SHA-256: f79c81ba54e916bde66d96827fa4d73e99688c4a0b7e4fbd5f26c520e5bc2559
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with multiple URLs pointing to compromised or disposable hosting. The primary purpose appears to be redirecting users through a series of links, likely to a phishing page or a malware download site.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 http://fk-fudosan.1nino3.com/app/webroot/img/userfiles/files/73721018714.pdf In PDF document text
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/1613d44890e14f---nukefutokara.pdfIn PDF document text
    • http://muzycznescyzoryki.pl/userfiles/file/1182984002.pdfIn PDF document text
    • https://mn-lawfirm.com/box/userfiles/file/95354838703.pdfIn PDF document text
    • https://aep-tc.com/cache/fck_files/file/5801359732.pdfIn PDF document text
    • http://mopi.eu/ckfinder/userfiles/files/67364352402.pdfIn PDF document text
    • https://saint-florentin.charcutier-traiteur.fr/ckfinder/userfiles/files/wutujujotujuzimuxari.pdfIn PDF document text
    • http://przedszkolenisko.pl/userfiles/file/55604393925.pdfIn PDF document text
    • https://mayersoffice.com/userfiles/file/16098997794.pdfIn PDF document text
    • http://magdrywall.com/project-new/christianbook/upload_images/file/sowozosotefavu.pdfIn PDF document text
    • http://de-ko-gmbh.com/ckfinder/userfiles/files/51171620972.pdfIn PDF document text
    • http://bakefruit.com/uploads/files/202109021807449317.pdfIn PDF document text
    • http://microsolder.hu/userfiles/files/95383824528.pdfIn PDF document text
    • https://dmitrovka-zn.ru/admin/ckfinder/userfiles/files/mororiri.pdfIn PDF document text
    • http://imaginove.eu/data/Files/4558097182.pdfIn PDF document text
    • https://sharenkon.com/files/5182495591.pdfIn PDF document text
    • http://www.yeosung21.or.kr/ckfinder/userfiles/files/1631073714.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/a1218b0a8e6354ea213940d940821e4a/76101061697.pdfIn PDF document text
    • https://dragonexpressml.com/userfiles/files/41131891076.pdfIn PDF document text
    • https://lashmakerpro.it/wp-content/plugins/super-forms/uploads/php/files/db241h9bpeo4e5jithrs2bk0n6/27014252581.pdfIn PDF document text
    • http://theeultimatenetworker.com/ckfinder/userfiles/files/44618619618.pdfIn PDF document text
    • http://phanphoiongnhuahoasen.vn/upload/files/25850026896.pdfIn PDF document text
    • https://xuantruongtech.com/images/ckeditor/files/64389845141.pdfIn PDF document text
    • https://dacoma.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16138ec84123cf---rinonuparomotitok.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=minor+arc+of+a+circle+formulaPDF 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_off0000b3cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB3CF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cbe1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCBE1 15508 bytes
SHA-256: 8f3db097df68b885378cb9dd92f3d9f7443b5322ee18dac94a1eb9ed76d4d586
font_02_sfnt_off0000f36c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF36C 10324 bytes
SHA-256: 12a872ecf509d299109cc27b01d49832e418bbe395af82daa3a735baec875179