Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4c3518a02242002…

MALICIOUS

PDF

89.2 KB Created: 2021-06-26 19:47:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b3220497ebdf6caca4b893d43fb582a6 SHA-1: e728ae1f65d9daa1fecb60703bec4275ff94c165 SHA-256: a4c3518a02242002d8cfc208c47696cc6d8e5816395d41512480e7ca3f00b006
156 Risk Score

Malware Insights

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

The PDF file contains a large number of links, many of which point to compromised WordPress upload directories. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

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 https://irlanc.ru/uplcv?utm_term=apple+galette+with+puff+pastry+ina+garten
    • http://maxitelt.no/wp-content/plugins/formcraft/file-upload/server/content/files/160a1fefbc97ba---997295162.pdf
    • http://montaze.org/democms/userfiles/file/87117835191.pdf
    • http://seasonsblinds.com/uploads/ckfinder/userfiles/files/81047545397.pdf
    • https://www.bouldersudbury.org/wp-content/plugins/formcraft/file-upload/server/content/files/160921de472748---55884683140.pdf
    • https://maspacientes.es/wp-content/plugins/super-forms/uploads/php/files/i7jnkcoh4t45utomjtukg0njuf/23877424786.pdf
    • http://aptchasers.com/FCKeditor/userfiles/file/rujikujixozipaduwa.pdf
    • https://digireg.nz/upload/91086513445.pdf
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/1608557a48656b---64218091491.pdf
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16089685abc1cd---sevunorow.pdf
    • http://victorylimo1.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083dfec15285---zafixibudi.pdf
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/763d00be67a10990ddc41e4432535c85/36588548866.pdf
    • http://krindustria.com.br/site/wp-content/plugins/formcraft/file-upload/server/content/files/160901b95d333b---jozupiwegazusegami.pdf
    • https://photographerin.agency/wp-content/plugins/super-forms/uploads/php/files/ps57rjeg301tt1505euahttrr1/99241646349.pdf
    • http://www.vandiestbrandstoffen.be/uploads/files/1281842754.pdf
    • http://fotossc.pl/_files/file/wakajotekasisa.pdf
    • http://skylineidaho69.com/clients/c/c7/c7306e0a9cc1d421caefa9c307ca601f/File/turifovodugujogilolanarob.pdf
    • https://xn--80afc2apd5n.xn--j1amh/upload/files/momawemure.pdf
    • http://manavpublicschool.org/manav/userfiles/file/gilabotelidavibuwakefimo.pdf
    • http://dermaktif.com/imgup/file/2106284947.pdf
    • http://beetsom.com/PROGRAM_FCKeditor_UserFiles/file/38653320860ca5063da323.pdf
    • https://www.letspassdriving.co.uk/wp-content/plugins/super-forms/uploads/php/files/2o2smtqrvrpo6hfql1r75r63pl/21703197528.pdf
    • http://brenna-ski.pl/userfiles/file/23950261788.pdf
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16077b91a86391---wogapufakiki.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_off0000f3c3.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF3C3 16792 bytes
font_01_sfnt_off00010bd5.bin
92a4c956a3bcf771696ac57b9dbcce5587cb69b3313abb74d4279df0bcea64fd
pdf-font-stream PDF embedded font (sfnt) at offset 0x10BD5 19340 bytes
font_02_sfnt_off00013e84.bin
b2dd06b7494037c250c9888260eedc62e399cd34439ee18e50920ebcfa27b62e
pdf-font-stream PDF embedded font (sfnt) at offset 0x13E84 10800 bytes