Malicious PDF — malware analysis report

Static analysis result for SHA-256 23d228feb9b6cc11…

MALICIOUS

PDF

79.4 KB Created: 2021-09-17 07:48:17 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: a7cee5b4a29f04146101bbac21a9a151 SHA-1: 529e4965c65dfc945c6d21ecf5ac6a43cbba69dd SHA-256: 23d228feb9b6cc11ebe0b2ebd84c0d6c636e1e93ce54cfbc8c07bf24fc60a96a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which are hosted on disposable domains or compromised CMS uploads, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery. No scripts were extracted, but the structure and URLs point towards a malicious document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 https://coretry.ru/uplcv?utm_term=free+games+for+android+tablet PDF link annotation
    • http://goksirkrupskimlyn.pl/img/upload/files/13701235924.pdfIn PDF document text
    • http://szguilong.com/userfiles/files/85657383198.pdfIn PDF document text
    • https://queensflower.nl/clientfiles/35205861267.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b9058146d8---marop.pdfIn PDF document text
    • http://stlukesfp.org/ckfinder/userfiles/files/temugepiven.pdfIn PDF document text
    • http://kleinschadenexperte.com/userfiles/file/10384538311.pdfIn PDF document text
    • http://xn----8sbnbd9chja.xn--p1ai/userfiles/file/41923256015.pdfIn PDF document text
    • http://ingore.cn/upload/files/15489550762.pdfIn PDF document text
    • http://fasson.vip/images/editor/files/pijusumiluxezusajoze.pdfIn PDF document text
    • http://harryreichert.de/uploaded_pics/News/file/golixizazofozog.pdfIn PDF document text
    • http://nek.ua/wp-content/plugins/formcraft/file-upload/server/content/files/161393259e250c---jegozop.pdfIn PDF document text
    • https://namphuctourist.com/userfiles/file/wonokosamarowezuwobu.pdfIn PDF document text
    • http://sanchariglobal.com/userfiles/file/zuvirejetanavetizatuk.pdfIn PDF document text
    • http://moscowprice.com/content/xuploadimages/file/4905512255.pdfIn PDF document text
    • https://creativesilhouettes.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16140e3dc15421---25330961556.pdfIn PDF document text
    • http://www.homefacelifters.com/wp-content/plugins/super-forms/uploads/php/files/09d79897a31c7744987aa23e1856e095/51039535443.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/c8b1d939b180628d45bc22c31fbeb17e/kotebobikosagi.pdfIn PDF document text
    • https://mauspro.net/upload/files/23334505353.pdfIn PDF document text
    • http://pillshop.ru/uimg/files/48216812906.pdfIn PDF document text
    • http://888spirits.com/userfiles/file/nukup.pdfIn PDF document text
    • https://wita.lt/images/files/14926065170.pdfIn PDF document text
    • 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_off0000d3fa.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3FA 16816 bytes
SHA-256: d4400fee610abca187a1734d600bcf281436728014951da47787984db2d9ab41
font_01_sfnt_off0000ffbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFBF 10812 bytes
SHA-256: a75f565b3e033c5e6cf2a7447f5a5c155e68630004c6af32a49d85cdf7341bf2
font_02_sfnt_off0001186f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1186F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1