Malicious PDF — malware analysis report

Static analysis result for SHA-256 e36321dcb9e0fa07…

MALICIOUS

PDF

95.7 KB Created: 2021-09-24 07:05:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: de22e6a0baeec0e137231ef204e735d6 SHA-1: 71a2280844f9459c1dcdeddf8d3fa691e0be9c84 SHA-256: e36321dcb9e0fa07fff0cedcc770a88e84c4d5210e2d6b2457b9a0eee7727b5c
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to various domains, many of which appear to be compromised or disposable hosting, forming a link farm. The presence of a 'download button' heuristic and the ClamAV detection as 'Pdf.Phishing.Trojan' strongly suggest a phishing or malware distribution attempt. Although no scripts were explicitly extracted, the PDF structure and link farm indicate an attempt to redirect users to malicious content, likely for downloading a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9941

Heuristics 7

  • 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.
  • 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://szjwwj.com/userfiles/file///54792609042.pdf In PDF document text
    • http://cermak-expo.cz/data/files/file/jimulejo.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/3d9851757aec8a186edbb1c41cb313b1/88305055735.pdfIn PDF document text
    • http://www.mustwalge.ee/data/content/files/zekamumipimujuzijodafepo.pdfIn PDF document text
    • http://kolaykanal.com/userfiles/files/32942587961.pdfIn PDF document text
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147ff52eb62e---towok.pdfIn PDF document text
    • https://bywuf.org/upload/editor/files/6857117017.pdfIn PDF document text
    • https://zzwgjx.com/d/files/dususanuter.pdfIn PDF document text
    • http://www.advancedevents.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613a48d8d24cf---73760918368.pdfIn PDF document text
    • http://ducthai.vn/userfiles/file/tepajovoxemizimusog.pdfIn PDF document text
    • http://8njl.com/userfiles/files/73996909491.pdfIn PDF document text
    • https://pabausa.org/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7fd55a828---wesutojota.pdfIn PDF document text
    • http://hzbmsj.com/images/upload/File/wuvobelirokitigut.pdfIn PDF document text
    • http://easytravel63.ru/ckfinder/userfiles/files/55500680046.pdfIn PDF document text
    • http://seoulmenu.com/uploads/files/xoduvufilebaf.pdfIn PDF document text
    • http://elitvorota.ru/f/file/53555563607.pdfIn PDF document text
    • https://pergamine.com/ckfinder/userfiles/files/91737726622.pdfIn PDF document text
    • http://thaoduocvn.com/userfiles/image/file/18035877141.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/161446df0d612a---julivek.pdfIn PDF document text
    • http://bdpq.hungminhits.com/files/uploaded/files/belimonowozedofos.pdfIn PDF document text
    • https://bharatiyabhashaparishad.org/ckfinder/userfiles/files/lojenezepewevod.pdfIn PDF document text
    • http://ssss-sangam.com/userfiles/file/72646597180.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/6naE_Nh8_CY/uplcv?utm_term=tamilcool+new+movie+download+comPDF 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://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_off000118da.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x118DA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000130ec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130EC 17460 bytes
SHA-256: 803c5613c770118e8e2af0cd3c74a6eb4f8c6bb7f3a5c8e4bbed36712ec5379a
font_02_sfnt_off00015e51.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15E51 10280 bytes
SHA-256: 80c84100c6c7ddc4826e14c49f29351a5beda23754787df11659b63d177824db