Malicious PDF — malware analysis report

Static analysis result for SHA-256 c903adfbca3cfb35…

MALICIOUS

PDF

82.9 KB Created: 2021-09-19 23:03:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 628ad4d6c8cf95052eeabe3db897ef9f SHA-1: 0dcbac1d528f43e665b7e5b049ca2a60f45ae3d0 SHA-256: c903adfbca3cfb35d280f206596cc32de7b19313b5842daa325f2c51fab91afe
66 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The ML classifier and PDF heuristics strongly indicate malicious intent. The sample contains numerous external URLs, with one specifically identified as a link farm designed to redirect users to potentially malicious sites. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest an attempt to direct users to external resources for further compromise, aligning with spearphishing tactics.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9917

Heuristics 4

  • 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://drafthe.ru/uplcv?utm_term=use+phone+as+keyboard+for+smart+tv PDF link annotation
    • https://activepymes.com/pub/file/54649641980.pdfIn PDF document text
    • http://master-sign.ru/ckfinder/userfiles/files/nonuxuva.pdfIn PDF document text
    • https://tennis94.fr/img/pics/files/sirugexebomu.pdfIn PDF document text
    • https://www.southdownscellars.co.uk/ckfinder/userfiles/files/wawikemeg.pdfIn PDF document text
    • https://speedwayinfo.hu/uploads/file/43895280310.pdfIn PDF document text
    • https://lemarko.com/userfiles/file/sofofuzukigotoxodotub.pdfIn PDF document text
    • http://wxhsbl.com/ckfinder/userfiles/files/20210905_161942.pdfIn PDF document text
    • https://krajkarka.cz/userfiles/file/38840240229.pdfIn PDF document text
    • http://bxbrdh.marketsearching.com/upload/files/wobifiteze.pdfIn PDF document text
    • https://www.alertgy.com/wp-content/plugins/super-forms/uploads/php/files/7017d4b27b22b46349537a9fc5045cbd/24595500384.pdfIn PDF document text
    • https://wilsonbarrera.com/inicio/wp-content/plugins/formcraft/file-upload/server/content/files/1613512edd1ada---javorod.pdfIn PDF document text
    • http://cohn-vossen.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138420aca90a---16059021490.pdfIn PDF document text
    • http://ellenia3.eu/userfiles/files/67867283599.pdfIn PDF document text
    • http://vinhomeshaiphong.net/app/webroot/img/files/99139890636.pdfIn PDF document text
    • http://stroisvias.ru/userfiles/file/bitada.pdfIn PDF document text
    • http://a-daily.jp/app/webroot/contents_img/files/didasolov.pdfIn PDF document text
    • http://nemochem.cn/upload/files/penaxelajekapasek.pdfIn PDF document text
    • http://hidropro.hu/upload/4660723771.pdfIn PDF document text
    • https://medtek.vn/storage/file/zadinalikebixumitaranoz.pdfIn PDF document text
    • http://romengo.com/ckfinder/userfiles/files/26760299203.pdfIn PDF document text
    • http://sb-78.ru/files/file/nubodikuzejebo.pdfIn PDF document text
    • http://xn----7sbbbizu2bxaod.xn--p1ai/userfiles/file/wujoruwewisemexez.pdfIn PDF document text
    • https://kopari.hu/files/file/23538033176.pdfIn PDF document text
    • http://leguido.net/files/28050179052.pdfIn PDF document text
    • https://bhandarisurgical.com/ckfinder/userfiles/files/biwaxegibuzegevorupikugij.pdfIn PDF document text
    • http://tulga.ru/editor/files/mujuxe.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_off0000dfd9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFD9 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f7f0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF7F0 11044 bytes
SHA-256: f7662d5cb3f7eee5144b48c2cdb7b2b7da09b8fe3be6e171e0f06adf6a4d3a84
font_02_sfnt_off0001114f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1114F 17244 bytes
SHA-256: 6e0ed0858c7429934c850d9402ca0372c534a1fbca979287541aecc5767d8779