Malicious PDF — malware analysis report

Static analysis result for SHA-256 c112fc2e36e753c1…

MALICIOUS

PDF

82.6 KB Created: 2021-09-05 11:29:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-20
MD5: 6a304b3c71b93f8dcabaf32b0c84013b SHA-1: 6daa4ad40677e00c353ae8e8cffef1106e3eb1d9 SHA-256: c112fc2e36e753c129231129f227f285e2ebefdf559b6c910fe0d5b904d91517
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to domains identified as disposable or compromised. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' suggests the document is designed to leverage SEO for malicious purposes by creating a network of links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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
  • 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://sendedianqi.com/upload_fck/file/2021-7-19/20210719034909704653.pdf In PDF document text
    • http://younewstoday.com/task/userimages/file/54932595507.pdfIn PDF document text
    • https://xn--64-mlcufjjaii0l.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/5ca98e1d9a51765100508a354b5008d2/5363727497.pdfIn PDF document text
    • http://xn--ob0bjxt9h99icicrvkksa421cwwp7hiv4d6a.com/ckfinder/userfiles/files/velotomibobepikobuziva.pdfIn PDF document text
    • http://robwalker.net/fckupload/file/jufuwejat.pdfIn PDF document text
    • http://aliancegroup.su/wp-content/plugins/formcraft/file-upload/server/content/files/160db3724d0da1---puvageb.pdfIn PDF document text
    • https://menokatea.com/ckfinder/userfiles/files/notewedu.pdfIn PDF document text
    • http://sterkrade.net/ckfinder/userfiles/files/modeb.pdfIn PDF document text
    • http://leylasuren.com/images/userfiles/imagefile/69727205798.pdfIn PDF document text
    • http://ahjygjg.com/upload_fck/file/2021-8-20/20210820000631289019.pdfIn PDF document text
    • http://totaleclipsenv.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f015b0b3ac---vuviwegewebubemabiwur.pdfIn PDF document text
    • https://parlagame.com/calisma2/files/uploads/94944099331.pdfIn PDF document text
    • https://kraftyz.in/ckfinder/userfiles/files/33210453736.pdfIn PDF document text
    • https://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/e74619e29db70ae88659f0a75f4e1bf4/12099776200.pdfIn PDF document text
    • http://globalquestconsulting.com/userfiles/files/rukumogiwofebudoj.pdfIn PDF document text
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/a366f83ad1ae9e1f568c7f87bfd6d5b5/pawekarujuwizupiguw.pdfIn PDF document text
    • http://www.annaleehuber.com/content_files/file/79355551192.pdfIn PDF document text
    • https://ambient-interier.cz/files/files/77600508195.pdfIn PDF document text
    • http://www.radanhorse.com/resource/files/75300444852.pdfIn PDF document text
    • https://suncables.co/images/file/noduwidopoxudon.pdfIn PDF document text
    • http://marcth.pl/media/fck/file/jofirezimozepitoji.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=tutorialspoint+os+pdf+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_off0000e04e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE04E 10508 bytes
SHA-256: 3aaf4cab7f5f3745a0da9298a909dd6cc9938e269374ee05e8b9425b34e27d18
font_01_sfnt_off0000f857.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF857 17116 bytes
SHA-256: ca116007725a87666450627b2026a72e18a3d6e8fbb315fe4301806994d69eed
font_02_sfnt_off00012486.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12486 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1