Malicious PDF — malware analysis report

Static analysis result for SHA-256 3c764eab675b8a55…

MALICIOUS

PDF

68.6 KB Created: 2021-09-30 19:45:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 841a96cfd24c15bc254bb89802b01b5b SHA-1: 94f3e9f15290c57347bda7f6ae4a0d23a7d53509 SHA-256: 3c764eab675b8a55f22ea698d6555f3e43c85582b4a75cbd68a0b8beda1acfa5
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, many hosted on compromised or disposable domains, indicative of a link farm used for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further supporting the malicious nature of the file.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://inwebjor.ru/uplcv?utm_term=types+of+rain+gauge+pdf
    • https://torbay.ru/images/uploads/file/9701110274.pdf
    • https://noursportevents.com/wheelmarine/userfiles/file/xivubufev.pdf
    • http://logicamail.it/draft/media/99489805874.pdf
    • https://syteq-pro.com/userfiles/file/47247227515.pdf
    • http://edilcfcostruzioni.com/userfiles/files/kazonutusoziwinikog.pdf
    • http://tamtamphat.com/upload/files/67735089748.pdf
    • http://fitviewer.de/files/file/99308989050.pdf
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/kgn497d5nq497nm44miufkenp5/taxoraridixuranefuwa.pdf
    • http://dieutrimun.myphamkangnam.vn/webroot/img/files/7364255279.pdf
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/1614b93cea59b3---96563786830.pdf
    • http://zhizhencn.com/filespath/files/20210922214950.pdf
    • https://philly.drinkpoint.com/uploads/files/dowarixatepe.pdf
    • http://formel1vermietung.de/userfiles/file/89099869561.pdf
    • http://hstairan.com/fckeditor/editor/filemanager/connectors/php/userfiles/file/zadijivufalunonadofukagi.pdf
    • https://erdemlerkoleji.com/resimler/files/78395697169.pdf
    • https://nomortiga.com/contents/files/10843495116.pdf
    • http://kiapelhrimov.cz/UserFiles/File/karugile.pdf
    • http://gr-chem.com/upload/files/fibusafapoxofagarulokutu.pdf
    • http://geobigoni.it/userfiles/files/mopalewavabezisemus.pdf
    • http://amsaneeraus.fi/userfiles/files/fixovomixejo.pdf
    • http://delfosventures.net/userfiles/files/76100263833.pdf
    • http://jamoncup.es/wp-content/plugins/formcraft/file-upload/server/content/files/161389c122c674---4734882140.pdf
    • https://verandapattaya.com/userfiles/files/50251658604.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ae7e.bin
d0a9edd5ea26b6fcd73a4d24982b109bca61f46b1f62ac5b3d5816dd52949b56
pdf-font-stream PDF embedded font (sfnt) at offset 0xAE7E 10708 bytes
font_01_sfnt_off0000c6fc.bin
2b667c10453de4b45b349202aa05e3f03977f7cb9038dd32335af3cec330b23c
pdf-font-stream PDF embedded font (sfnt) at offset 0xC6FC 15092 bytes
font_02_sfnt_off0000eccf.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xECCF 16792 bytes