Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4f21f5d4ede6826…

MALICIOUS

PDF

80.5 KB Created: 2021-09-21 16:18:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: cc60c80ebd8474bc9ec54d3ef7cd7257 SHA-1: 1c017edcfba7b240a9c75ea13b81b82dcfe938c6 SHA-256: a4f21f5d4ede68262320bf6b159e3106e38326db89fe94f2f6567fc43e2450c0
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by multiple heuristics, including a critical ClamAV detection for 'Pdf.Phishing.Trojan'. The presence of numerous links on disposable hosting, some pointing to compromised CMS upload directories, suggests a phishing or malware distribution attempt. The primary URL, 'https://wastran.ru/uplcv?utm_term=download+chatgum+apk', indicates a lure for downloading an application, likely malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://wastran.ru/uplcv?utm_term=download+chatgum+apk PDF link annotation
    • http://www.otevrenysklep.cz/ckfinder/userfiles/files/51830733136.pdfIn PDF document text
    • http://ain.proximeo.com/ckfinder/userfiles/files/poretiguzajabaveme.pdfIn PDF document text
    • https://esperanzadeavila.com/fotos/file/zezogis.pdfIn PDF document text
    • http://www.arborvitae.cz/ckfinder/userfiles/files/6138382391.pdfIn PDF document text
    • http://www.primalegal.eu/wp-content/plugins/super-forms/uploads/php/files/g9807p65k2cl421oltkj2b73j1/30063311617.pdfIn PDF document text
    • http://poddertradingandindustries.com/userfiles/file/6238922459.pdfIn PDF document text
    • https://hosvagyok.hu/userfiles/file/lusowopijikuvosujap.pdfIn PDF document text
    • http://hoangnamjsc.com/upload/files/14543574744.pdfIn PDF document text
    • http://epwuae.com/userfiles/file/79257984652.pdfIn PDF document text
    • http://physocare.com/Images_upload/files/masuwe.pdfIn PDF document text
    • https://www.helpfulhunks.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1613d1c9f9ede3---44767076721.pdfIn PDF document text
    • http://worldwidestationeryholdings.com/files/file/lojatatitujeni.pdfIn PDF document text
    • http://actybrain-consult.com/Upload/files/zikara.pdfIn PDF document text
    • http://zhodnoceni-penez.cz/is/images/FCKeditor/File/gevatu.pdfIn PDF document text
    • https://funcarele.com/ckfinder/userfiles/files/zedisitalixobidepugofuw.pdfIn PDF document text
    • http://dealershop.es/userfiles/file/lixokemolow.pdfIn PDF document text
    • http://clubmaniacr.com/campannas/file/wubozubutujixivixobe.pdfIn PDF document text
    • http://moveisgarciadigital.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/16145652d76c8b---36648859638.pdfIn PDF document text
    • http://omni-links.com/images/blog/file/tubut.pdfIn PDF document text
    • https://consultingexpert.eu/fckeditor/userfiles/file/xusoregapopuvose.pdfIn PDF document text
    • http://russia-ex.com/images/blog/file/68027861821.pdfIn PDF document text
    • http://erulingua.hu/uploads/content_files/files/wugame.pdfIn PDF document text
    • http://poketomecam.com/uploads/files/fesapefipujazajotu.pdfIn PDF document text
    • http://hagelkonzept.de/userfiles/file/ditipiporimelabinogotuj.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_off0000d5ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD5AB 18008 bytes
SHA-256: 5488989b684d0d83803846b48d00fb03665c8f7599ccf9a98928e928eada966b
font_01_sfnt_off000103d3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103D3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011bea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BEA 10748 bytes
SHA-256: 8170595f4175d50fd6c5e3911dd6dd8b1769aa82c80b6ac6baac4c9b3a90c9bb