Malicious PDF — malware analysis report

Static analysis result for SHA-256 2a5374bc29fd07c3…

MALICIOUS

PDF

71.9 KB Created: 2021-09-13 12:10:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: bdbbc80e2ebbf37b76ae7a2c69f1ec97 SHA-1: 1b78afcdbd917cf1d748cafb20a452f4bd86192d SHA-256: 2a5374bc29fd07c30c833e3c7fc74807f1e62a8c4ce5af47f153afbc72ad6d34
126 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 a large number of embedded URLs pointing to various domains, suggesting it functions as a link farm to lure users to potentially harmful websites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating a programmatic approach to creating the malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://wastran.ru/uplcv?utm_term=dice+throne+rules+2.2 PDF link annotation
    • http://kolbiko.com/images/uploads/file/77973970908.pdfIn PDF document text
    • http://kahsport.cz/userfiles/file/rufuturalevanirago.pdfIn PDF document text
    • http://3mfa.com/images/editor/files/sobivum.pdfIn PDF document text
    • http://caycanh.vn/images/fck/file/14412941486.pdfIn PDF document text
    • http://yeditepegumruk.com/userfiles/31972284768.pdfIn PDF document text
    • http://branonperformance.com/ckfinder/userfiles/files/susanukojutukarovu.pdfIn PDF document text
    • http://rdasesores.gestconcursal.com/editor/ckfinder/userfiles/files/takejokoseluluwo.pdfIn PDF document text
    • https://leunamgroup.com/wp-content/plugins/super-forms/uploads/php/files/b1c74bc9a7787a1c670b42042fe5fa55/38708417771.pdfIn PDF document text
    • https://10kshot.com/customerinterview/ckfinder/userfiles/files/wulaxi.pdfIn PDF document text
    • https://wangwangcamp.com/uploads/files/202109040503324039.pdfIn PDF document text
    • https://polandpools.com/contents/files/5479842929.pdfIn PDF document text
    • http://centroolosprato.it/userfiles/files/ramogakubazup.pdfIn PDF document text
    • https://dentalrud.com/userfiles/file/juwegoselisevetiwanofar.pdfIn PDF document text
    • http://autosoftware.company/autoresponders_images/files/zewomiwob.pdfIn PDF document text
    • http://choragwica.pl/userfiles/file/15542087487.pdfIn PDF document text
    • https://foodphotoshop.com/userfiles/files/womuvazimimesasi.pdfIn PDF document text
    • https://ppntassone.it/dati/upload/file/fazasibude.pdfIn PDF document text
    • http://pcwenhua.com/uploadimg/file/16308195521343040538.pdfIn PDF document text
    • https://vyaspublicschool.com/ckfinder/userfiles/files/wudidipelikakizifisufi.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/rknlf3btnj262t56qe3c81he8k/zasixamapamazororogizubiv.pdfIn PDF document text
    • http://yameitecl.com/ckfinder/userfiles/files/20210913_135306.pdfIn PDF document text
    • http://alacarte-design.de/userfiles/file/wasagebag.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_off0000b85c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB85C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d073.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD073 10452 bytes
SHA-256: eb45bc15941ee8ea5a61811ae488c383636ddb60fc73fed3c01f2939bdfc86dc
font_02_sfnt_off0000e833.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE833 16468 bytes
SHA-256: 09d6b04e1d8b8bbc67e571d16c9589e1ce9e8406c8fb6b598a53501108e1b219