Malicious PDF — malware analysis report

Static analysis result for SHA-256 a961fb5ec636123d…

MALICIOUS

PDF

80.4 KB Created: 2021-10-11 23:20:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: b727712acff1449a038a6ffbc000f193 SHA-1: c347ba61e5173e593033ade95dc30fa154442349 SHA-256: a961fb5ec636123d4e2dc0432938c928c8754757ea1907e58ccda65e82cb48d9
156 Risk Score

Malware Insights

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

The PDF document contains a link farm directing to numerous other PDF files hosted on various domains, many of which appear to be compromised or disposable. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The structure suggests an attempt to obscure the true destination by using multiple layers of redirects and potentially compromised hosting.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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://xn--hazrdner-r4a10d.com/alisveris/yollanan_resimler/file/12499697713.pdf In PDF document text
    • http://safeabortionnepal.com/userfiles/file/93441381499.pdfIn PDF document text
    • https://yournew.site/wp-content/plugins/super-forms/uploads/php/files/ls1bvtjpejr9q0qnf3h11vv3ks/87856141212.pdfIn PDF document text
    • http://dongphat.net/upload/files/nibutafonuwoputag.pdfIn PDF document text
    • http://ngor2-3.com/file_media/file_image/file/66198593694.pdfIn PDF document text
    • http://praguynakorn.com/praguynakorn/picture/datapro/files/laxutowufumurifituna.pdfIn PDF document text
    • http://jocoseatee.com/userfiles/files/33350471917.pdfIn PDF document text
    • http://gtlmarinefuel.com/userfiles/file/wusizimirisit.pdfIn PDF document text
    • http://datev.hu/ckfinder/userfiles/files/50625466079.pdfIn PDF document text
    • https://opescom-store.com/uploads/FCK_files/file/besifexasowujojinijuwi.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/munuwonojedog.pdfIn PDF document text
    • http://dorp.pl/userfiles/files/fotipojafor.pdfIn PDF document text
    • http://www.melodypods.com/wp-content/plugins/formcraft/file-upload/server/content/files/161407e92e6882---88457216022.pdfIn PDF document text
    • https://rocksoliddesigns.biz/userfiles/file/84776815846.pdfIn PDF document text
    • http://odontoflash.eu/userfiles/files/16901989378.pdfIn PDF document text
    • http://manpukulivermore.com/uploads/files/50641139489.pdfIn PDF document text
    • http://peterpan1996.it/userfiles/files/nopunotavikikoxamudu.pdfIn PDF document text
    • https://francoisdaulte.com/ckfinder/userfiles/files/96988946824.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614be00ca33b6---zofaridaxaviv.pdfIn PDF document text
    • http://pwr-tech.ru/userfiles/file/32474345544.pdfIn PDF document text
    • https://angelsforwarriors.org/userfiles/files/31519063400.pdfIn PDF document text
    • http://boracayg.com/FileData/ckfinder/files/20211007_0FDB12A858279C24.pdfIn PDF document text
    • http://feedproxy.google.com/~r/Xvkpad/~3/D9plVHj2VOU/uplcv?utm_term=safe+method+for+birth+controlPDF 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_off0000d363.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD363 19060 bytes
SHA-256: 4c89a117296467026f65ea9991173076bed1628da0bc1f71642c0c87c926a933
font_01_sfnt_off000103b3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x103B3 10788 bytes
SHA-256: 869f22f67b3258230edaf949d9d3794ea6b84434487f880ddd7102a9a28612ba
font_02_sfnt_off00011c4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11C4F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1