Malicious PDF — malware analysis report

Static analysis result for SHA-256 f34100b757860e5a…

MALICIOUS

PDF

79.1 KB Created: 2021-09-17 11:17:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 557effb3b4c043dac310dcb006827459 SHA-1: 8fde053eb9cbb2de22fcabd8eea0b6e0b5409186 SHA-256: f34100b757860e5ad7f4a581939e29c64d34c94b66fa09d9cf95d44ec84d13ff
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, specifically identified as a phishing trojan by ClamAV. The document contains numerous embedded URLs, many of which point to disposable hosting and form a link farm, suggesting an attempt to obscure the ultimate destination or to distribute a payload. The presence of a redirector with a 'piano game download apk' UTM term indicates a lure to trick users into downloading potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://alistairmills.com/ckfinder/userfiles/files/30268176455.pdf In PDF document text
    • http://huiking.cn/uploads/file/011910163417.pdfIn PDF document text
    • http://cofetariafraguta.ro/UserFiles/file/xilazogafan.pdfIn PDF document text
    • http://lnianemarzenie.pl/userfiles/file/zewujoz.pdfIn PDF document text
    • http://gsmontaggi.it/userfiles/files/toxapegoruteriko.pdfIn PDF document text
    • https://mangalargalux.com.br/ckfinder/userfiles/files/37045074174.pdfIn PDF document text
    • http://anhuifan.com/upload_fck/file/2021-9-2/20210902204825132397.pdfIn PDF document text
    • https://quangcaowebsitecomvn.xemlaco.com/uploads/files/sofowusujupujavodubu.pdfIn PDF document text
    • https://mercerapparelss.com/userfiles/files/7716327900.pdfIn PDF document text
    • http://cybernet.asia/UserFiles/File/gerir.pdfIn PDF document text
    • https://maychieuvinh.vn/upload/files/lokilosewapimifomodilino.pdfIn PDF document text
    • https://zabulgaria.org/userfiles/file/tajuwebudofamudifufi.pdfIn PDF document text
    • https://stcatherine.ac.ug/wp-content/plugins/formcraft/file-upload/server/content/files/16136436c0273e---gotapexelazozetonilotukip.pdfIn PDF document text
    • http://mousike.it/img_ins/files/75707946400.pdfIn PDF document text
    • https://777mto.info/contents/files/vopizaraxiwivogule.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/ecb6bc71b6193a67f813594710387cfd/29480316849.pdfIn PDF document text
    • http://canadianartistic.com/userfiles/file/14022735345.pdfIn PDF document text
    • http://hrdiborice.cz/erucom1/files/files/xumama.pdfIn PDF document text
    • http://ippon.lv/uploads/File/5853997833.pdfIn PDF document text
    • http://peneleos.pl/userfiles/file/78024769131.pdfIn PDF document text
    • http://highspiritsmusic.com/ckfinder/userfiles/files/29647671262.pdfIn PDF document text
    • http://diamantina-joaillerie.com/ckfinder/userfiles/files/petujoredinidorudokomore.pdfIn PDF document text
    • http://firstcuwire.com/file_media/file_image/file/kuvowofumifenadevoke.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/GLLx1DTH0VQ/uplcv?utm_term=piano+game+download+apkPDF 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_off0000d096.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD096 10548 bytes
SHA-256: 0e81277b55da6c10a0d66df16ade5ca8bcae9c896b59b5fa221ae4e1e9e51096
font_01_sfnt_off0000e860.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE860 18044 bytes
SHA-256: 946d9d1da00b1e132f31323adbd0439dcce8a577a946ed03bbcf8108571126f0
font_02_sfnt_off00011686.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11686 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1