Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6ace91298503637…

MALICIOUS

PDF

72.3 KB Created: 2021-09-23 12:05:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 4bdb03412376380f3f4b59b711458967 SHA-1: 57bf7e9c8dddc1a9d673b6aca4645d8d5aba38c8 SHA-256: a6ace9129850363708190fc28054dd9537c9519e10af934359c4348da1512ca4
134 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by multiple heuristics, including ML classification and ClamAV detection, indicating malicious intent. The presence of numerous external URIs, many pointing to disposable hosting and acting as a link farm, suggests a phishing or malware distribution scheme. The document body, though heavily obfuscated, contains metadata indicating it was generated by wkhtmltopdf, a tool often used to create PDF documents from web content, further supporting the lure of downloading files.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://cructi.ru/uplcv?utm_term=tubemate+download+for+windows+7 PDF link annotation
    • http://hoangnamjsc.com/upload/files/96390274809.pdfIn PDF document text
    • http://worshipedia.net/sites/default/files/file/31486959916.pdfIn PDF document text
    • http://giaodantanthaison.com/Images_upload/files/lejezinetapilalew.pdfIn PDF document text
    • https://robustbrakes.com/administrator/imagetemp/file/56507723754.pdfIn PDF document text
    • http://health-bridge.in/upload/file/wetaluzojodenu.pdfIn PDF document text
    • http://e-district.org/userfiles/file/64373132294.pdfIn PDF document text
    • http://andlupa.com/userfiles/file/73193252511.pdfIn PDF document text
    • http://land89.com/ckupload/files/pikuvopofak.pdfIn PDF document text
    • http://drsrkbedcollege.com/ckeditor/ckfinder/userfiles/files/juvenekugika.pdfIn PDF document text
    • http://siciny.eu/userfiles/file/28004636469.pdfIn PDF document text
    • http://fra2ange.it/userfiles/files/givuwixukiduvatevofabakan.pdfIn PDF document text
    • http://thuonghieutoancau.vn/uploads/files/15764976286.pdfIn PDF document text
    • http://ttlh.vn/storage/ckfinder/files/63346377456.pdfIn PDF document text
    • http://acupunctuuryao.nl/ckfinder/userfiles/files/90079264699.pdfIn PDF document text
    • http://giustizianuova.it/userfiles/file/kuzobebumomakifuweberu.pdfIn PDF document text
    • http://fmafirm.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/ruxowamavalumor.pdfIn PDF document text
    • http://omonetach.pl/foto/ilustracje/file/32954010079.pdfIn PDF document text
    • http://entone.es/wp-content/plugins/super-forms/uploads/php/files/d70a672daef07f976de271498ded2d19/vuvipisakana.pdfIn PDF document text
    • http://kaztelcom.kz/ckfinder/userfiles/files/92878749414.pdfIn PDF document text
    • http://attlas.center/userfiles/file/forimesasu.pdfIn PDF document text
    • http://fcraregistration.com/UploadedData/file/55172496543.pdfIn PDF document text
    • http://bigbulkbags.com/survey/userfiles/files/banetokavuwepi.pdfIn PDF document text
    • http://exosportsante.fr/ckfinder/userfiles/files/62216785263.pdfIn PDF document text
    • http://dvg.asia/ckfinder/uploadfiles/files/78909458776.pdfIn PDF document text
    • http://ipjanah.ir/wp-content/plugins/super-forms/uploads/php/files/nvrmklvc67au5n43mlnsdk54j5/rakobilekexetukupinew.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_off0000b8cf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB8CF 16280 bytes
SHA-256: e8286ffd4b07238aa45d29fe3dcce7d0e4d4fdf3b75dde279460dff08e889920
font_01_sfnt_off0000e277.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE277 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000fa8e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFA8E 10852 bytes
SHA-256: 118eef3e830bcc8a86f4d4ffae5f967dc68dfcd3df62315e86704bd6c2bd7aaf