Malicious PDF — malware analysis report

Static analysis result for SHA-256 52160d12657e9225…

MALICIOUS

PDF

76.8 KB Created: 2021-09-05 09:16:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 1a370522905f0f3665d5eceab6bdf54f SHA-1: 238d7780b8171ec71b46cabe9827fb3c6c38f85a SHA-256: 52160d12657e9225f61dee22fdc036a16c13d8fa60810d39d321e8afec04b752
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to external sites hosted on potentially compromised or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The presence of external URI heuristics and link farm indicators supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://musikkursus.dk/userfiles/file/fifimezorop.pdf In PDF document text
    • http://www.themixchange.com/userfiles/files/13061538052.pdfIn PDF document text
    • https://trade.inter-ural.ru/ckfinder/userfiles/files/6909496583.pdfIn PDF document text
    • https://evergreencans.com/userfiles/file/87175006058.pdfIn PDF document text
    • https://cissud.com/uploads/ck_editor/files/tazevew.pdfIn PDF document text
    • http://farmaciafici.com/userfiles/files/potovepixegesu.pdfIn PDF document text
    • https://amenajarisiconstructii.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16084e6dc3341c---79314352352.pdfIn PDF document text
    • http://chinamakina.com/userfiles/file/lifaxidanasarobevivan.pdfIn PDF document text
    • https://medpressa.ru/files/file/81715439362.pdfIn PDF document text
    • http://ahkjt.com/upfile/file/ligugabetirob.pdfIn PDF document text
    • http://kaowei.tw/image/files/20210527_184809.pdfIn PDF document text
    • https://chocoinmobiliario.com/wp-content/plugins/super-forms/uploads/php/files/44f3225bafcd41df12d68019ec252bfe/xulidopaligulagu.pdfIn PDF document text
    • https://stefandes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160815a8e52382---20321104623.pdfIn PDF document text
    • http://www.sunarsurdurulebilir.com/wp-content/plugins/super-forms/uploads/php/files/eth0j31btjh8uokgv3i68of621/xagek.pdfIn PDF document text
    • http://alexdisinfestazioni.com/userfiles/files/55832041146.pdfIn PDF document text
    • http://epoxidice.ro/mm/file/84725968600.pdfIn PDF document text
    • https://www.rath-catering.de/wp-content/plugins/formcraft/file-upload/server/content/files/1606efbb72e480---fupitawimutivawireke.pdfIn PDF document text
    • http://s-privod.ru/userfiles/file/4353438886.pdfIn PDF document text
    • http://santabruna.cl/upload/file/zupizidamewuxujuj.pdfIn PDF document text
    • http://southport1969.com/clients/861680/File/vepoxonasub.pdfIn PDF document text
    • http://www.iamgoingto1996.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a25b84b52b8---3001092727.pdfIn PDF document text
    • https://iwnta.com/userfiles/file/jazekirati.pdfIn PDF document text
    • https://autoschiller.de/wp-content/plugins/formcraft/file-upload/server/content/files/16071a1603f790---67105162278.pdfIn PDF document text
    • https://stayatrosetta.com/wp-content/plugins/super-forms/uploads/php/files/6e3p9ld55h5l5mjdvf4ek923pd/4931042772.pdfIn PDF document text
    • http://yavuzselimvakfi.org/resimler/site/files/15015197995.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/A3Ryygt5BCM/uplcv?utm_term=rain+bird+anti+siphon+valve+manualPDF link annotation
    • 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_off0000c636.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC636 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000de48.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE48 18024 bytes
SHA-256: 5771fa2dd48c4df27b999b428cf0f2fa3caabb37e7a15cdfa56592ed7cc87dc8
font_02_sfnt_off00010c6e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C6E 11008 bytes
SHA-256: c9bfc31c7d3e06da2e820ccb13306d641166f16cf3750fa304b9a4cb8e0b37a3