Malicious PDF — malware analysis report

Static analysis result for SHA-256 8cd9324c1184d253…

MALICIOUS

PDF

68.7 KB Created: 2021-10-02 13:21:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 068dbfd7c32026b14357fa33997f7ae8 SHA-1: 3c6d6bbfda97f62ab173c3f7cbbbc13fc62d1975 SHA-256: 8cd9324c1184d253b26abc73e9a339329ea4731c769a999aef2e2689b289be62
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF was flagged by multiple heuristics as malicious, including a high-confidence ML classifier and ClamAV detection. It contains numerous external links, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users. The presence of embedded URLs and the nature of the heuristics indicate the PDF's primary function is to redirect users to malicious external sites, likely for phishing or to download further payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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=that+works+for+me PDF link annotation
    • https://pgprojekt.pl/Upload/file/vojul.pdfIn PDF document text
    • http://eros-arena.com/eros/userfiles/file/25099793664.pdfIn PDF document text
    • http://magooferta.pl/uploads/fck/file/85365798514.pdfIn PDF document text
    • http://rosniyom.com/userfiles/files/50912573886.pdfIn PDF document text
    • https://triosms.com/userfiles/file/gutepapininofepokux.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614be781eda56---mizadizekejitufavimofak.pdfIn PDF document text
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16133bb8d11234---jumexijexidobipobojosexo.pdfIn PDF document text
    • http://honghuibio.com/d/files/78344896510.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/16156b012c62ac---lobevofoxebopagewumufog.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16155a02278187---38746091421.pdfIn PDF document text
    • http://quranday.org/userfiles/file/dusabix.pdfIn PDF document text
    • http://e-pisanie-prac.pl/famprojekt_z_serwera/images/file/36532744649.pdfIn PDF document text
    • http://www.armstrongre.com/files/files/96162305168.pdfIn PDF document text
    • https://renhedc.com/uploads/files/202109261237445322.pdfIn PDF document text
    • http://lienming-rubber.com/uploads/files/202109051624071173.pdfIn PDF document text
    • https://www.grdr.org/paidel/ckfinder/userfiles/files/vifin.pdfIn PDF document text
    • https://livres-d-art.com/ckfinder/userfiles/files/judijufujezafuxiwu.pdfIn PDF document text
    • https://xenang-mitsubishi.com/fckupload/file/57984957822.pdfIn PDF document text
    • http://jonme.net/ckupload/files/tosumofotumubux.pdfIn PDF document text
    • http://gzwep.com/img/file/2021910124359.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/a3505cfab29b251cad718194b4cb1b8b/93068726403.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_off0000afb3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAFB3 10380 bytes
SHA-256: 650b0c1d69f02774ce678ce7d6a289cf0a1f37ff39b7609523e9504e9d4169b0
font_01_sfnt_off0000c759.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC759 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000df6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF6B 15024 bytes
SHA-256: 5dfab93aa53f5135bbb2daed87bf4f6d23450ec789b335a02e5bf6b8ca67b935