Malicious PDF — malware analysis report

Static analysis result for SHA-256 cdaa6a7510d33512…

MALICIOUS

PDF

121.2 KB Created: 2021-07-03 06:11:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 2870bb109fb2807ee78eb6f7bf58c198 SHA-1: 84ec4f07519327ce517dff12f8a534cebdffe338 SHA-256: cdaa6a7510d3351283787933f1e195b509ec197f24bde2d1930af95175e91d52
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS uploads and disposable hosting, suggesting a phishing or malware distribution scheme. The document body was unreadable, but the presence of numerous external links strongly supports the link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://xn--12cm8caae5d9a0a0a1dxk6dd.com/user_img/files/56230527608.pdf In PDF document text
    • https://spaslask.pl/wp-content/plugins/super-forms/uploads/php/files/al43vo6j744lbtp5ahvtdjl737/76828519252.pdfIn PDF document text
    • http://thermcom.cz/userfiles/file/22186061387.pdfIn PDF document text
    • https://www.hospedeagora.com.br/wp-content/plugins/super-forms/uploads/php/files/1qom0qpr25f08d3lbjp13ri35i/54165228377.pdfIn PDF document text
    • https://alsterparkett.de/wp-content/plugins/super-forms/uploads/php/files/4ndek6ivc7ktt3dcotvlf82jne/22488322850.pdfIn PDF document text
    • http://accomplishtheimpossible.com/userfiles_ati/file/20820683619.pdfIn PDF document text
    • https://takiminsahada.com/wp-content/plugins/super-forms/uploads/php/files/372hfmgal3gjbh2j9gttmfa896/kodizusisunuxopiluwos.pdfIn PDF document text
    • http://www.rec39.ru/wp-content/plugins/super-forms/uploads/php/files/4a2af3621ab82642e32fd11a4ffd6b6f/nukunakedopevef.pdfIn PDF document text
    • http://mastervgtour.by/var/upload/file/75008665193.pdfIn PDF document text
    • https://bokseinstituttet.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160af7165ce3a5---xatuwomekirafufi.pdfIn PDF document text
    • http://www.dadosefatos.net.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c6dd817f28---29903000941.pdfIn PDF document text
    • http://litho-and-co.fr/ckeditor/upload/files/tabovexofajaru.pdfIn PDF document text
    • http://kapelski.pl/userfiles/file/fopigevuligomiru.pdfIn PDF document text
    • https://www.kbstephens.com/wp-content/plugins/super-forms/uploads/php/files/36dbdf4ad4761dad47907e2021bcdefc/56504058926.pdfIn PDF document text
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/28a143a377035ceaba9e1769bf590276/dazidosowusobate.pdfIn PDF document text
    • https://www.couleurs-et-jardin.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a631bcb1e60---49484587913.pdfIn PDF document text
    • http://minutemen-jrotc.com/clients/84940/File/62586094676.pdfIn PDF document text
    • http://szpital-sulecin.pl/images/fckfiles/file/wewedogupufevorebeletu.pdfIn PDF document text
    • http://global-poseg.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093b8d9b42ac---22394421853.pdfIn PDF document text
    • https://amesmedicalservices.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a936396c02e---devuzivatiwokekejowado.pdfIn PDF document text
    • http://studiofelician.com/userfiles/files/padubidaselet.pdfIn PDF document text
    • http://dishandspoonproductions.com/ckfinder/userfiles/files/86711012940.pdfIn PDF document text
    • http://salondebellezaanamariaromero.es//ckfinder/userfiles/files/pobazivanara.pdfIn PDF document text
    • http://paradisetourkorea.com/FileData/ckfinder/files/20210604_CD4EE85FA6E66E87.pdfIn PDF document text
    • https://nationalcardsolutions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608f93cd55618---disusud.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606c998f864d8---nebew.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/nta2oebiufe2rvsfmjr16td92u/18287728883.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/zMnd8XtcwSM/uplcv?utm_term=the+end+schoolPDF 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_off00017bbf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x17BBF 17568 bytes
SHA-256: 1284ce1161975cb3a9e5e37ba074e3aa676511cc12ece0abc28dadd335ada5ca
font_01_sfnt_off0001a977.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1A977 9976 bytes
SHA-256: e617bf2ac175207de3f29199f07637f4ab8aa530d75e0d1c33ab85676c81628e
font_02_sfnt_off0001bf7c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1BF7C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1