Malicious PDF — malware analysis report

Static analysis result for SHA-256 5c8101c7d4584f1b…

MALICIOUS

PDF

75.0 KB Created: 2021-08-21 22:44:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 654af30fdecc3f3a395490d20e42b615 SHA-1: 20e87bf96792b1f7abbf3aa8052394dc3f1dc347 SHA-256: 5c8101c7d4584f1bfa9365b6f8c291a360fae7a0a9af0d812d8554c9082ced14
156 Risk Score

Malware Insights

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

The PDF 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 pointing to compromised WordPress upload storage, suggesting a phishing or malware distribution scheme. The embedded URLs, particularly those hosted on potentially compromised domains, are key indicators of this attack pattern.

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 http://dom-nenilovo.ru/wp-content/plugins/super-forms/uploads/php/files/233778125bf317a2dd0a87be7b1d1471/6706726588.pdf In PDF document text
    • http://mellorymotors.ru/admin/ckfinder/userfiles/files/50301742514.pdfIn PDF document text
    • http://vasilii-orlov.fun/wp-content/plugins/super-forms/uploads/php/files/1ea2b0adae6256cc7cda6fb86c446a11/zijivolesekunarorawigid.pdfIn PDF document text
    • http://kapsalonvogue.nl/files/file/3987937421.pdfIn PDF document text
    • https://club-sports.net/uploads/products/files/90233373086.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/uk9hj64ork8e5kgupv9sv3s1k5/36855931514.pdfIn PDF document text
    • https://harpethvalleypto.org/wp-content/plugins/super-forms/uploads/php/files/76c527240212a6465e2c78141dfdd953/vujoge.pdfIn PDF document text
    • https://drsubhashawale.com/ckfinder/userfiles/files/takop.pdfIn PDF document text
    • https://giustofiori.it/file/joxodivosalozoz.pdfIn PDF document text
    • http://vitanova-cattery.com/upload/file/neraviwuzined.pdfIn PDF document text
    • http://viaterrestre.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1610a9bc6c1a0a---dapoxekivel.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/suwufadudibinewetimokatoz.pdfIn PDF document text
    • https://www.bountyvacation.com/wp-content/plugins/formcraft/file-upload/server/content/files/16076251487b25---sibekutu.pdfIn PDF document text
    • https://atlanthealth.com/wp-content/plugins/super-forms/uploads/php/files/afb19f007351c50ed4d36e85cf7afd0e/rafafuf.pdfIn PDF document text
    • https://imagebeaute.fr/userfiles/file/meluwamazafiwegudi.pdfIn PDF document text
    • https://ocvirapuato.com.mx/wp-content/plugins/super-forms/uploads/php/files/d8150fd1f00f00a531dcdbeaa10f4e9a/65972901606.pdfIn PDF document text
    • https://www.budgetskemaet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/1608216ae8d069---vupigubixuko.pdfIn PDF document text
    • https://narimasu-chintai.net/jcfiles/file/27531118213.pdfIn PDF document text
    • http://verypool.cn/images/upload/File/guragarazigomuxukikam.pdfIn PDF document text
    • https://glass-haus.ru/wp-content/plugins/super-forms/uploads/php/files/ccfbab85f8c303f98cf298488ec769cb/kafijizowuzaledo.pdfIn PDF document text
    • https://farmstead.tw/farmstead/upload/files/16555873529.pdfIn PDF document text
    • http://effektfilm.de/files/file/34236929474.pdfIn PDF document text
    • http://24cvety.ru/upload/files/283038844.pdfIn PDF document text
    • http://auroraenergyproject.it/userfiles/files/67583660141.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=difference+between+iodometric+and+iodimetric+titrationPDF 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_off0000c260.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC260 10652 bytes
SHA-256: 27d1a4dad461b75f819f836db762cca01d7fdc73e83aea0584d73a0919351466
font_01_sfnt_off0000dad2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDAD2 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f2e4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2E4 16336 bytes
SHA-256: 25b73e2232f951f4bac5597bf6191378f20dbc50a2a42cd7c3a85e444e757107