Malicious PDF — malware analysis report

Static analysis result for SHA-256 a11383254aa366ae…

MALICIOUS

PDF

81.7 KB Created: 2021-09-23 14:58:50 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 6922d545db7134f50319876b92cb854a SHA-1: 64ff2813d072eeccb08caacc34c8f8bf4b614c39 SHA-256: a11383254aa366ae6f8661fac24dcae29d876e0e94f2f62984d5831f267ca37b
134 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, many of which point to disposable hosting and are structured as link farms, suggesting a phishing or malware distribution scheme. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior. While no scripts were extracted, the overall structure and URL patterns strongly suggest the PDF is intended to trick users into downloading a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://igigeothermal.jp/userfiles/file/53987250572.pdf In PDF document text
    • https://perbloland.com/userfiles/file/dajet.pdfIn PDF document text
    • https://zhongzing.com/uploads/files/202109071330215773.pdfIn PDF document text
    • http://solarissoft.com/img/userfiles/files/43232132953.pdfIn PDF document text
    • http://climtech.com/files/files/2195397316.pdfIn PDF document text
    • https://laughteronlineuniversity.com/images/upload/files/zugoravuj.pdfIn PDF document text
    • http://ventensis.lt/public/ckfinder/userfiles/files/podalojajawun.pdfIn PDF document text
    • http://teranor.com/ckfinder/userfiles/files/48731827682.pdfIn PDF document text
    • http://ctcinsulator.com/uploads/file/75669870607.pdfIn PDF document text
    • https://etcbt.com/userfiles/file/nomeriribodovejigopidadi.pdfIn PDF document text
    • http://i-dron.cz/data/file/91741911424.pdfIn PDF document text
    • https://wanfutemple.urwaydesign.com/data/file/userfiles/files/88835882008.pdfIn PDF document text
    • http://inoxbienhoa.com/upload/files/17269141779.pdfIn PDF document text
    • https://zivotzaokny.eu/res/file/92215617325.pdfIn PDF document text
    • https://linhquan-group.com/upload/ck/files/fatod.pdfIn PDF document text
    • http://drironcat.com/images/file/kexawuzetoxe.pdfIn PDF document text
    • https://rajakedua.com/contents/files/9149791288.pdfIn PDF document text
    • https://canoe.ro/Extras/ckfinder/userfiles/files/66431914134.pdfIn PDF document text
    • http://52fotki.ru/ckfinder/userfiles/files/66317649381.pdfIn PDF document text
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614729091d0ea---soduzamujizodabupa.pdfIn PDF document text
    • https://ngaa.org.au/application/third_party/ckfinder/userfiles/files/20566280511.pdfIn PDF document text
    • https://www.lowdoc-loans.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161429bcab5111---91638108840.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=pictures+apk+downloadPDF 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_off0000d79c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD79C 18736 bytes
SHA-256: 8a93301112a7a411da638fdbc0af7efe925249ddf3b17c50cd74a03c881391aa
font_01_sfnt_off00010827.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10827 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001203e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1203E 10788 bytes
SHA-256: 3bacc9924d9d8ca149f4053c4097cc82aed3237eeb7205b33f14013ee13b46ab