Malicious PDF — malware analysis report

Static analysis result for SHA-256 91a9ce3320cd7ae2…

MALICIOUS

PDF

79.4 KB Created: 2021-09-12 22:55:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 120fe55f30eb2b3f64f9b71b3fc2d4f0 SHA-1: 9de76fe858aca622209c2cdcb687d6771636667f SHA-256: 91a9ce3320cd7ae2c22e2cb3aa5a8ca9ad0b3b77eb14da134655106f4c76943b
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it functions as a link farm. The embedded URLs point to domains that are either compromised or disposable, suggesting an intent to lure users to malicious sites. The PDF structure and numerous external links are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://synerhu.ru/uplcv?utm_term=angry+birds+legends PDF link annotation
    • http://goodfortune.hk/UpLoadFile/file///lumiwavozuw.pdfIn PDF document text
    • http://a-mega.ua/images/uploads/file/kojopilosixeduw.pdfIn PDF document text
    • http://lorofilmes.com/Uploads/ckfinder/userfiles/files/39803050444.pdfIn PDF document text
    • http://8njl.com/userfiles/files/rawadomezobadapanonapu.pdfIn PDF document text
    • https://lesartsdansmonjardin.com/userfiles/file/20210907102727.pdfIn PDF document text
    • http://gostium.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613df376dadaa---59152015122.pdfIn PDF document text
    • http://www.samuitns.com/image/upload/File/83957373376.pdfIn PDF document text
    • http://nutrizionisti.eu/public/thread/risorse/file/newapizerij.pdfIn PDF document text
    • http://sicilalluminio.it/userfiles/files/baxoxemujonovosorovexe.pdfIn PDF document text
    • https://coil.hk/upload/files/62103117843.pdfIn PDF document text
    • http://ubytovna-krumlov.cz/userfiles/file/zawub.pdfIn PDF document text
    • http://yh-nutri.com/filespath/files/20210902111041.pdfIn PDF document text
    • http://grupomarsamo.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130972d7f80d---87698031750.pdfIn PDF document text
    • http://blfimmobiliare.com/userfiles/files/mupizibenurupipajimom.pdfIn PDF document text
    • http://halvani.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613927a86c934---76101662791.pdfIn PDF document text
    • http://templeton.sk/userfiles/file/vesekezagodatogobetazowu.pdfIn PDF document text
    • http://morebricks.com/ckfinder/userfiles/files/87600692064.pdfIn PDF document text
    • http://pazarziraat.com/userfiles/file/wujegiwobaku.pdfIn PDF document text
    • http://www.szphotar.com/admin/img/files/72372023609.pdfIn PDF document text
    • http://boras-sjuharad.boj.se/uploads/userfiles/files/xesajejijo.pdfIn PDF document text
    • https://ingatlansos.hu/images/userfiles/file/91033261240.pdfIn PDF document text
    • http://cjcounsel.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/87007351106.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/d87e0a31403361a32bc18f079e24c641/91615318805.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_off0000ce0b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE0B 19068 bytes
SHA-256: 7fe6913a2c8a230d2fd0a83459e56091fe756a9484b185fb4a449aa5257e4d8d
font_01_sfnt_off000100da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100DA 10276 bytes
SHA-256: 48bc16d672f341788defb5f732bd921fe666af3ff778793e2d14108725bf24ab
font_02_sfnt_off000117d9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117D9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1