Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3a4172ece8f1648…

MALICIOUS

PDF

143.7 KB Created: 2021-06-27 07:21:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c4a87481e5751ff8452898682e78f36c SHA-1: 4873b676d1f59971d9de4ec3a783de6f4cb7985c SHA-256: a3a4172ece8f164863ccb5873f3fd1560f3196aad67e370e421f6d3546bc2730
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript, which is a common technique for exploiting PDF vulnerabilities or redirecting users. Multiple heuristics indicate the PDF is part of a link farm, with many external URIs pointing to compromised or disposable hosting, suggesting an attempt to distribute malicious content or phish for information. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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 https://huntic.ru/uplcv?utm_term=the+molecules+that+function+to+replicate+dna+in+the+cell+are
    • http://adirondackseafood.com/ckfinder/userfiles/files/4290919050.pdf
    • https://maxim-catering.de/wp-content/plugins/super-forms/uploads/php/files/dmjp5318hbrchgmfauhh14pmis/40288267259.pdf
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/a2a94beae837c67f9480be9a11da557a/jekemijujikir.pdf
    • https://ahi.com.ua/wp-content/plugins/super-forms/uploads/php/files/efac14c136b8565b94de723594763077/wuregirijajelefukufa.pdf
    • http://skup-laptopow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607408cfa1fa4---wesekovemosavexigabudaju.pdf
    • http://www.franklinwebdesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ddf19c73b5---xepuzenipuxomemig.pdf
    • http://vaness-sens.fr/ckfinder/userfiles/files/15695522892.pdf
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160c887dce7b6a---wugavuziva.pdf
    • https://aprilboya.com/userfiles/file/jineboruteresepomepid.pdf
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/892331501c0a66bc2733d3f2455c245f/53768317590.pdf
    • http://riggi.ru/userfiles/file/boxapujuzetufex.pdf
    • http://arunimaflavours.com/userfiles/file/wegaluwetubejepusuzazofad.pdf
    • https://40parables.com/wp-content/plugins/super-forms/uploads/php/files/972bbee55c70a88a666bccc9772a224e/nupelal.pdf
    • https://nsck-cykelmotion.dk/userfiles/file/8157467462.pdf
    • https://avenirpourtous.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a6c55a72cbf---vixizixanomebopuwed.pdf
    • https://auf.vn/wp-content/plugins/super-forms/uploads/php/files/fjt2itao724a94molkbof4v6q5/25609650220.pdf
    • http://www.iso-clean.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609d0f7852ec1---viviragokupelureb.pdf
    • https://imahima.xyz/js/ckfinder/userfiles/files/ripekujulasevod.pdf
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608fe8b416215---64324309184.pdf
    • https://www.idahomedia.com/wp-content/plugins/super-forms/uploads/php/files/1285d46e7b9d445ec3b693ddb5049e01/86574693161.pdf
    • https://reitinguok.lt/userfiles/file/10944267099.pdf
    • http://southfieldhigh1973.com/clients/2/27/27a5067865c8334ad4a5a1fd7642c928/File/38451648309.pdf
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d7f5e44295f---fibebapi.pdf
    • https://daquin-ferriere.fr/userfiles/file/sasovej.pdf
    • http://www.northeastmarquees.com/wp-content/plugins/super-forms/uploads/php/files/45648aff5c177672cec59d7958466f02/66999900990.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001cd7b.bin
a7ace0e23e38294c9cb277c84534f39a85daa662b40cea5588c3aadfa9489fa5
pdf-font-stream PDF embedded font (sfnt) at offset 0x1CD7B 18896 bytes
font_01_sfnt_off0001ff5a.bin
e90347a18a20652e9c6a2fc0ca5e8fcec4c31c5c76f8ceef81b4ba04e03a5f73
pdf-font-stream PDF embedded font (sfnt) at offset 0x1FF5A 10948 bytes
font_02_sfnt_off0002188b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x2188B 16792 bytes