Malicious PDF — malware analysis report

Static analysis result for SHA-256 8c5b2330d4a56f1c…

MALICIOUS

PDF

78.9 KB Created: 2021-10-06 15:14:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: a265ea4df4d9fb6eebacc5753d8fc3a9 SHA-1: 9e51c0761043fb43ded69b99957ea5baf0a7844b SHA-256: 8c5b2330d4a56f1c771737134adc7422ec4e765c4744d4f91a25e7a69c118448
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URLs, many hosted on compromised WordPress sites or disposable domains, suggesting a link farm designed to redirect users. While no scripts were explicitly extracted, the PDF structure and heuristic firings point towards a phishing or malware distribution lure, likely delivered via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://laborke.ru/uplcv?utm_term=preposition+exercises+for+class+2 PDF link annotation
    • https://jurvamartin.com/userfiles/file/1256900723.pdfIn PDF document text
    • http://grandviewgroupresort.com/upload/files/fiwejurozupoxovasaluvakug.pdfIn PDF document text
    • http://riverla.vn/uploads/userfiles/file/71614801897.pdfIn PDF document text
    • https://joebalogh.ro/imagini_ws/bepali.pdfIn PDF document text
    • https://er-cardiff.com/eurostyl/photos/file/68812360779.pdfIn PDF document text
    • https://sv-fin.ru/wp-content/plugins/super-forms/uploads/php/files/e052c4cdbea17bdc4ba188477ad37733/10207054087.pdfIn PDF document text
    • https://www.teppiche-waschen-hamburg.de/wp-content/plugins/formcraft/file-upload/server/content/files/161445b0a51436---54314911097.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/dk370qm0sq8ik24tnj2c7t9rm8/mipexirazezurofe.pdfIn PDF document text
    • http://baiduvpn.com/upload/files/6468459966.pdfIn PDF document text
    • https://virker-ikke.dk/files/37526076938.pdfIn PDF document text
    • http://greenearthgardens.org/userfiles/budezetasuvuxonaka.pdfIn PDF document text
    • http://conblocmanado.com/pics/file/rigisapixez.pdfIn PDF document text
    • http://dekobonner.de/userfiles/file/jutemoseserov.pdfIn PDF document text
    • https://sportyou.fr/ckfinder/userfiles/files/61009745894.pdfIn PDF document text
    • https://divanich96.ru/admin/ckfinder/userfiles/files/78371753152.pdfIn PDF document text
    • https://shiprapublication.com/uniformkontakt/userfiles/image/files/76491309171.pdfIn PDF document text
    • https://nistd.in/userfiles/file/dutuvekasadije.pdfIn PDF document text
    • https://citytrafik.nu/images/file/fidujapowenub.pdfIn PDF document text
    • http://mastera-mix.ru/ckfinder/userfiles/files/likapugobefa.pdfIn PDF document text
    • http://milkyway-vn.com/upload/files/worabovejepifabawalajok.pdfIn PDF document text
    • http://saltokisport.com/uploads/files/3322564256.pdfIn PDF document text
    • http://stagelight.pl/userfiles/files/84584754882.pdfIn PDF document text
    • https://cauthinh.com/luutru/files/5355214558.pdfIn PDF document text
    • https://jmtours.co/aym_image/files/84101658889.pdfIn PDF document text
    • http://kamkmori.cz/ckfinder/userfiles/files/xogenumenezobidufegamewux.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_off0000caf9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCAF9 19180 bytes
SHA-256: 47d4a2e5bbb844465ba447b0a9f0b1798c0c580073c90d260f6a72fc548d21b1
font_01_sfnt_off0000fcde.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFCDE 10696 bytes
SHA-256: 7c7c95c8709c6b926458ed3215d6ae453b73077b055b09255e9ac3b600a618a8
font_02_sfnt_off0001159c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1159C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1