Malicious PDF — malware analysis report

Static analysis result for SHA-256 68f8a4bf581dda05…

MALICIOUS

PDF

83.9 KB Created: 2021-10-06 15:55:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 7ab53e03f201582ea3d9c951d0cb89b5 SHA-1: 5ab11976f0008dcea0fccf2945342be249b8ea5c SHA-256: 68f8a4bf581dda05cfa52f25a60bfc703e6cb61c8a5f0cef4db859ebdb5882b9
126 Risk Score

Malware Insights

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

The PDF was flagged by ML and ClamAV as malicious, with heuristics indicating it functions as a link farm on disposable hosting. The embedded URLs point to various PDF files hosted on different domains, suggesting a phishing or malware distribution campaign. No scripts were extracted, but the overall structure and heuristic firings strongly indicate a malicious intent to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://unite-chem.cn/upload/files/86916285114.pdf In PDF document text
    • http://www.tecnobor.com/ckfinder/userfiles/files/91265997395.pdfIn PDF document text
    • https://promobryansk.ru/userfiles/files/69883495296.pdfIn PDF document text
    • https://khogiaydantuonghanquoc.com/images/news/file/90983121506.pdfIn PDF document text
    • http://firewaterdamagedfw.com/test/fckeditor/uploadfiles/file/13865665076.pdfIn PDF document text
    • https://speakingparrot.com/upload/ckfinder/files/mupijut.pdfIn PDF document text
    • http://ladyqueen.it/userfiles/files/gajovisigipuzuxejaw.pdfIn PDF document text
    • https://perfecthospitals.com/ckfinder/userfiles/files/85151525000.pdfIn PDF document text
    • http://bamila.vn/luutru/files/28032913230.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/14365377663.pdfIn PDF document text
    • https://korvioinfotech.com/ckfinder/userfiles/files/bexotatusewiw.pdfIn PDF document text
    • https://kaskad-74.ru/images/uploads/9775508715.pdfIn PDF document text
    • http://fmmvn.net/userfiles/files/sujotefo.pdfIn PDF document text
    • http://aromamahabaleshwar.com/ckfinder/userfiles/files/dukuxosanigop.pdfIn PDF document text
    • http://contelex.it/userfiles/files/58895898590.pdfIn PDF document text
    • http://mariancozma.com/_user/file/12323787398.pdfIn PDF document text
    • https://g55net.com/webpagebuilder/ckfinder/userfiles/files/putarasetabo.pdfIn PDF document text
    • http://bularz-auto.pl/images/userfiles/file/14500067705.pdfIn PDF document text
    • http://nhasachconggiao.com/luutru/files/80117558742.pdfIn PDF document text
    • https://www.fecomerciomg.org.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613f55edee3f0---futizokutalijivozimano.pdfIn PDF document text
    • http://agppi99.pretty-match.com/upload/files/dabutaponiwapinobosizodux.pdfIn PDF document text
    • http://mtjjt.com/2013/upload/article/files/210909085646251744gjbnd.pdfIn PDF document text
    • http://downtowncincyhotels.com/core_degree/admin/images/cms_imagesfiles/13840735310.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=choose+the+word+which+is+opposite+in+meaning+to+the+keyword+factitiousPDF 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_off0000dcec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCEC 18844 bytes
SHA-256: 174fcede01b0e3b834b6e865c2dfb1ca943afe7aa044d7191d1070537b5999e2
font_01_sfnt_off00010e25.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E25 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001263c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1263C 11444 bytes
SHA-256: 2ef7577a37d0d8b3349e67d7baea96dca89c70d243db523aa7d2d87a99e9f634