Malicious PDF — malware analysis report

Static analysis result for SHA-256 5633aacfd198f12a…

MALICIOUS

PDF

84.7 KB Created: 2021-09-11 16:11:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 370424db17c0c5737fc9daec208596e2 SHA-1: 43dbca7f91115478d3ba3628365938f928e75769 SHA-256: 5633aacfd198f12aa6e46af518d33b5316f44b6c2f2b8edc4c3a74bb341b3c55
126 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various PDF files hosted on different domains, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing further malware. The document body is heavily obfuscated and contains metadata from wkhtmltopdf, suggesting it was generated programmatically rather than being a user-authored document.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://tectrongim.com/uploads/files/fatum.pdf In PDF document text
    • http://cjcounsel.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/genitaluzanu.pdfIn PDF document text
    • https://rowsontw.com/shopadmin/upload/files/85378825192.pdfIn PDF document text
    • http://lenosada.sk/editor_uploads/files/45971113303.pdfIn PDF document text
    • https://afgventuregroup.com/cfiles/file/jididubivuxurobifi.pdfIn PDF document text
    • https://dascalita.ro/app/webroot/files/userfiles/files/79255747896.pdfIn PDF document text
    • http://ahzgbh.news-read.com/upload/files/kurofipiwelaxorage.pdfIn PDF document text
    • http://maivietnamesecotati.com/uploads/files/91508655930.pdfIn PDF document text
    • https://china-glass-mosaic.vegner.com/userfiles/files/20210906_135135.pdfIn PDF document text
    • http://energyexcess.com/userfiles/file/80670417474.pdfIn PDF document text
    • http://lawyergz.net/uploadfile/files/294275206.pdfIn PDF document text
    • https://badrivishal.com/media/xafobiladutigo.pdfIn PDF document text
    • http://juncheng.tw/upload/files/jedakataxegura.pdfIn PDF document text
    • http://rambud.pl/uploaded/file/76213354608.pdfIn PDF document text
    • http://www.kingsmen-cmti.com/upload/files/wikapomajilijarizam.pdfIn PDF document text
    • https://alajuusa.ee/media/contents/file/5102120398.pdfIn PDF document text
    • http://cableesmaltado.com/d/files/vakezukiluxezugile.pdfIn PDF document text
    • https://maintogelonline2.bet/contents/files/xalapebeko.pdfIn PDF document text
    • https://orangcar.com/app/webroot/upload/files/rogovagilu.pdfIn PDF document text
    • http://csc0512.com/userfiles/file/20210904152031_l3wrtr.pdfIn PDF document text
    • http://khacvietlaser.vn/public/images_news/files/gobinajowap.pdfIn PDF document text
    • http://psychologkmalinowska.pl/ckfinder/userfiles/files/45591420789.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/b444142617d09c034080391b871f3d69/mawifimonis.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/A3Ryygt5BCM/uplcv?utm_term=how+to+make+space+on+your+android+phonePDF 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_off0000e51e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE51E 17796 bytes
SHA-256: 16311d80c38dd015d97ea8aafed0854c78a92b58c8fcac3b3aee1bf7925a9331
font_01_sfnt_off0001137c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1137C 11116 bytes
SHA-256: e77a7a17d873a401995212820e79b9d8df5768771ce29b12cdf9d2381136b347
font_02_sfnt_off00012d4c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12D4C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1