Malicious PDF — malware analysis report

Static analysis result for SHA-256 21beb2a48689f8a9…

MALICIOUS

PDF

72.2 KB Created: 2021-09-23 05:16:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-03
MD5: bfd0e8ce24e1c4702a4b0efecf382f00 SHA-1: e97896f3c4f5d33ae912e41010332fb0881e8a58 SHA-256: 21beb2a48689f8a936ec457c9af6fd73cf83054a6dc47a79f0740d92d199ac7e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to compromised WordPress sites and disposable hosting, indicating a link farm designed to redirect users to malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this. No scripts were extracted, but the overall structure suggests a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

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://catamma.ru/uplcv?utm_term=android+os+is+developed+by PDF link annotation
    • http://paitoonbox.com/userfiles/files/pasudixavuro.pdfIn PDF document text
    • http://prunay-en-yvelines.fr/ckfinder/userfiles/files/xufija.pdfIn PDF document text
    • http://onlytech-tunisie.com/userfiles/file/34866388976.pdfIn PDF document text
    • http://litroshaber.net/resimler/files/titozevuzilo.pdfIn PDF document text
    • https://verner.lt/images/files/poligaromixoneberuwufove.pdfIn PDF document text
    • http://master-sign.ru/ckfinder/userfiles/files/73856209290.pdfIn PDF document text
    • https://kuechentreff-schmid.de/wp-content/plugins/super-forms/uploads/php/files/1g73e0fsijeps2p2hq5oacv4n0/21528898315.pdfIn PDF document text
    • http://peak-experience-japan.com/images/blog/file/jofunodaxijemixedopi.pdfIn PDF document text
    • http://jumpstart.mobi/userfiles/file/18773678882.pdfIn PDF document text
    • https://aguiapromocional.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16148c25a300e0---tezuwo.pdfIn PDF document text
    • http://xn--90aoa5aj.xn--p1ai/ckfinder/userfiles/files/1888319491.pdfIn PDF document text
    • https://profix.fr/ckfinder/userfiles/files/32142418281.pdfIn PDF document text
    • http://champaigncursillo.com/userfiles/file/62022272436.pdfIn PDF document text
    • https://madhubanindiancuisine.com/nbloom/fckuploads/file/wokivedobuzidupuzoz.pdfIn PDF document text
    • http://wpklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/93502831391.pdfIn PDF document text
    • http://cargologicru.com/sadm_files/6845086402.pdfIn PDF document text
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133bf051a7bd---baluku.pdfIn PDF document text
    • http://unionasset.net/file_upload/spaw_upload/file/20210902014034.pdfIn PDF document text
    • https://lokmangal.co.in/wp-content/plugins/super-forms/uploads/php/files/2df894f0d2c02b51e41c8f83f76bb1a2/35573756364.pdfIn PDF document text
    • http://laskod.hu/userfiles/file/nivixoziluzim.pdfIn PDF document text
    • http://tuhocxuatnhapkhau.com/uploads/ckfinder/files/29438007183.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_off0000b89f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB89F 16760 bytes
SHA-256: d51d8e0d3840f0e327ab1dadd24b02e4141e1947092bc01a8bc08a27bb73084a
font_01_sfnt_off0000e426.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE426 10424 bytes
SHA-256: e03fa57f1765bcba644c5fcffc4036b57e79473fa25bbd4368f2b4cf7c1871e8
font_02_sfnt_off0000fba6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBA6 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1