Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f3e53fd9c3d14b7…

MALICIOUS

PDF

81.7 KB Created: 2021-10-15 19:08:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 81dd806139756f2e01713b5cf10f11fd SHA-1: ceb3c2586b8f3d895c9b2784b96b98ff7ccf8b90 SHA-256: 6f3e53fd9c3d14b7c3ed0f595207a49d4e4b484ee5bf39e1bb6ee10cf4f0c918
156 Risk Score

Malware Insights

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

This PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or trojan distribution attempt. It functions as a link farm, containing numerous URLs pointing to compromised CMS uploads and disposable hosting, likely to obscure the ultimate destination and evade detection. The presence of multiple PDF link farm heuristics strongly suggests a malicious intent to redirect users to harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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 http://colleges-in-tamilnadu.com/FCKeditor/userfiles/file/21149021161.pdf In PDF document text
    • http://fjzy18.com/image/uload/files/36065204091.pdfIn PDF document text
    • http://samtekelektrik.com/files/59127077698.pdfIn PDF document text
    • http://nhatrangpalacehotel.com/app/webroot/upload/files/bunazesajumojofatakoja.pdfIn PDF document text
    • http://ore-processing.ru/d/files/55037361559.pdfIn PDF document text
    • http://fipjp.com/userfiles/file/93933703658.pdfIn PDF document text
    • http://www.electricman.in/demo/frontend/web/uploads/files/58052607880.pdfIn PDF document text
    • https://letstravelforacause.com/miet/assets/files/12297627674.pdfIn PDF document text
    • http://eco-building.cz/UserFiles/File/zufiwus.pdfIn PDF document text
    • https://smartbrand.ro/mm/file/vuwezewuxazepuwinasizuru.pdfIn PDF document text
    • http://xn--h49al33a2zdp0eo1x.com/DATA/file/20211006102217.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613298e05b2b1---51778417182.pdfIn PDF document text
    • https://archielectronics.com/userfiles/files/ridalezager.pdfIn PDF document text
    • http://mariellatriolo.it/public/file/86561429791.pdfIn PDF document text
    • http://e-sportis.com/images/upload/tupimojiredejunanuf.pdfIn PDF document text
    • http://gf-location.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16149e94412bf4---vixapamotavina.pdfIn PDF document text
    • http://adabaskimerkezi.com/upload/file/gewudomuvaga.pdfIn PDF document text
    • http://laiyi-art.com/userfiles/file/retobeburivu.pdfIn PDF document text
    • http://ingmontagna.com/userfiles/files/mipojesim.pdfIn PDF document text
    • https://aventura-agence.lu/userfiles/files/zipapokivir.pdfIn PDF document text
    • http://1mosref.ru/ckfinder/userfiles/files/52211697252.pdfIn PDF document text
    • http://thuduchouse.vn/pics/file/37226243049.pdfIn PDF document text
    • http://officeharbor.com/pdtInfo/gubuxa.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/161361fc67283a---27385248020.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Gsjc/~3/BGAemAmcdTc/uplcv?utm_term=how+to+get+z+souls+xenoverse+2PDF 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_off0000db9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB9A 10552 bytes
SHA-256: f0ea86a784baea2612f5fd07d4ff93fbdb43d193e4b21e82ab36a9842a55e6ac
font_01_sfnt_off0000f3fd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3FD 17640 bytes
SHA-256: f0a49ae17735e000e985cd14db8a8617183b8be23b2c9c0dad302e59e1523e05
font_02_sfnt_off0001216b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1216B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1