Malicious PDF — malware analysis report

Static analysis result for SHA-256 73aa4b252a9e2183…

MALICIOUS

PDF

76.3 KB Created: 2021-09-27 06:19:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 0ce51e3c6333a6900044238763a7881c SHA-1: 7da310a578b843a5e73c9a7e503cb8de80283129 SHA-256: 73aa4b252a9e2183e8395acc008d75c8b84c3d63e53f8e5db02fa3446daa88ae
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and a machine learning classifier indicated a high probability of maliciousness. Numerous embedded URLs were found, many pointing to compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The primary attack pattern involves leveraging these links for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://medvor.ru/uplcv?utm_term=slender+man+origins+android PDF link annotation
    • http://careerhack.net/wp-content/plugins/formcraft/file-upload/server/content/files/16135dcea11437---15089040315.pdfIn PDF document text
    • http://jr.ac.th/ckfinder/userfiles/files/bazekizu.pdfIn PDF document text
    • https://seedcambodia.org/htdocs/cljr/data/files/5934837205.pdfIn PDF document text
    • http://thelonerangerfanclub.com/ckfinder/userfiles/files/53617091162.pdfIn PDF document text
    • http://solyaris.pro/admin/ckfinder/userfiles/files/jerajuz.pdfIn PDF document text
    • https://stepweystudy.com/ckfinder/userfiles/files/3150635983.pdfIn PDF document text
    • http://kemmurad.com/webroot/img/files/tunafik.pdfIn PDF document text
    • http://olympiad-bigben.ru/ckfinder/userfiles/files/44219612125.pdfIn PDF document text
    • http://kopdesign.nl/userfiles/file/jasuvosuteros.pdfIn PDF document text
    • http://ansatrans.ru/admin/ckfinder/userfiles/files/foremufedigamazawanas.pdfIn PDF document text
    • http://stromzeleny.cz/file/benama.pdfIn PDF document text
    • https://ascii.tn/web/cgi/file/liduzuxemotavibip.pdfIn PDF document text
    • http://jikaramen.com/uploads/files/63026397747.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/161419976d0ca3---lovigenulukulepadekupip.pdfIn PDF document text
    • https://mchs.kz/userfiles/File/sibizawokakorokuvigawim.pdfIn PDF document text
    • http://imhkayseri.com/resimler/files/59463790854.pdfIn PDF document text
    • https://lynnesnaturaltreats.com.au/wp-content/plugins/super-forms/uploads/php/files/05db3f0281edbd95579584e75cbf5532/takizepojuwoxibibilafide.pdfIn PDF document text
    • http://gk-eventus.ru/admin/ckfinder/userfiles/files/nupogatogedumovigatule.pdfIn PDF document text
    • https://growyourmoney.in/userfiles/files/58830913471.pdfIn PDF document text
    • http://shinhwajudan.com/userData/board/file/xepuxapidaz.pdfIn PDF document text
    • http://daiichigroup.net/uploads/news_file/16947696720.pdfIn PDF document text
    • http://riskhedgetech.com/uploaded/file/11828421596131f5cad641d.pdfIn PDF document text
    • https://tumsad.org/img/editor/image/file/jiwajozexusorum.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_off0000c038.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC038 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d84f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD84F 10568 bytes
SHA-256: 6b601b915044a98b63cf52b61e2ae8ee94a59c2c692b5747edcde8de0912cc66
font_02_sfnt_off0000f011.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF011 19732 bytes
SHA-256: b16e428fd77a045dac7730930a33e21ec104b06c97a9e003bbf11031e96dbe8a