Malicious PDF — malware analysis report

Static analysis result for SHA-256 ccb709551df5ab7c…

MALICIOUS

PDF

91.8 KB Created: 2021-09-02 22:00:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 42da9b57c2986c1f055c0642d4e858c8 SHA-1: 13eb41b9eaf8db1c7375aced083631cede70413f SHA-256: ccb709551df5ab7c00f9a65b3c2933b8012a698c23b58320986b68df4cd9dc1a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS uploads or disposable hosting, indicating a link farm designed to distribute malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious PDF lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://allytemp.ru/uplcv?utm_term=measure+theoretic+probability+book+pdf PDF link annotation
    • http://softwarefactory.nl/images/file/gutibetikuka.pdfIn PDF document text
    • http://ncdesign.it/userfiles/files/mojojamabemuj.pdfIn PDF document text
    • http://www.neocota.com/fckimages/file/jaxupoforororotumemu.pdfIn PDF document text
    • http://ggmtc.net/userfiles/files/31070422305.pdfIn PDF document text
    • http://powerfalcon.net/uppic/files/gevonalazewaxeruvoruzoj.pdfIn PDF document text
    • http://ntrc.biz/clients/f/f0/f0759d16aca5b3dfc9163ee994587b7f/File/tofepezizezibazujupixoxus.pdfIn PDF document text
    • http://www.peretprod.ro/content-images/file/zogarefu.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/29a2419a9dd26971f36b8feeddde9a01/wawimadabelujoroluvexiz.pdfIn PDF document text
    • https://dmvassociates.com/wp-content/plugins/super-forms/uploads/php/files/88a8a87440f143534792bcf5acafdd5e/60289173248.pdfIn PDF document text
    • http://denki-shonan.com/uploadsfile/71625781557.pdfIn PDF document text
    • https://evocative.ru/wp-content/plugins/formcraft/file-upload/server/content/files/160c0e41c53c8f---jimoj.pdfIn PDF document text
    • http://ahkkpcm.org/userfiles/wolitit.pdfIn PDF document text
    • http://studioassociatoemc.com/userfiles/files/85686643934.pdfIn PDF document text
    • https://morabia.fi/images/file/69818192863.pdfIn PDF document text
    • https://ukmalayalamnews.com/userfiles/file/migopukugoturebopomi.pdfIn PDF document text
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1610a121919e2e---fupurizekasobigujura.pdfIn PDF document text
    • http://rocincorporated.com/domain.com/images/dynamic_pages/file/605011593.pdfIn PDF document text
    • https://taevlingar.se/images/pages/file/futixowadun.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b5d6c2185d3---12014261639.pdfIn PDF document text
    • http://boulderdivorcelaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085517f12878---pizina.pdfIn PDF document text
    • https://www.peeryhotel.com/wp-content/plugins/super-forms/uploads/php/files/e9975e0cb6d0529fecbdc72c2aa5ff4e/91488780550.pdfIn PDF document text
    • http://twfbs.com/ckfinder/userfiles/files/11967725929.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_off00010128.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10128 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001193f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1193F 11052 bytes
SHA-256: 510094805f7b5fe3d6e9091c807d935749b99bef511bb44df0d3f664663a8642
font_02_sfnt_off000132e9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x132E9 17932 bytes
SHA-256: 05c4f146910c18c2fb19ee04aef42ec8365aed5802537e9c7bbea5bd4995f082