Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c735fe6a9837eea…

MALICIOUS

PDF

81.1 KB Created: 2021-09-03 23:19:19 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9f3c682dbb083b7eb9fa6e179d5121a0 SHA-1: 052de96196720e1fecba5c06f676c0b6e9b371d9 SHA-256: 4c735fe6a9837eeac9baf4c066f9efe29ac7612172af980da1ef4c588e3fccfe
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised WordPress sites utilizing the Formcraft plugin for file uploads. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution. The presence of link farms on potentially compromised CMS platforms suggests an attempt to obscure the final malicious destination or leverage existing infrastructure for distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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://test.uebersetzungen-nesselberger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612358a3c6299---dusomenulusas.pdf
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/1f295196149cefb214c8a84da41385a1/sijogunakujov.pdf
    • https://www.bouwenaaneensterkwerkgeversmerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1609bf9105531f---33247203984.pdf
    • https://baongochoa.com/upload/file/defudisenevumudupove.pdf
    • http://dabien.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/1610035726023c---59833707726.pdf
    • http://bukvoznaika.ru/ckfinder/userfiles/files/jibarejekax.pdf
    • http://tetraeng.it/userfiles/files/gezajojusufabevinepaba.pdf
    • https://liniagdanskzydowo.pl/files/47900057300.pdf
    • http://sushistoryus.com/uploads/files/97900737510.pdf
    • http://www.holderit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608626324e9be---votoselivurutaxagegon.pdf
    • http://mijneigenlift.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16082a61b071c7---purakulesaxapuki.pdf
    • http://gardensyellowcab.com/admin/images/file/lokijikorarivuxode.pdf
    • http://cesishotel.lv/res/wysiwyg/file/22292626825.pdf
    • http://www.a-fairys-choice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa73248a625---73740411484.pdf
    • https://gulfcans.com/home/madarmun/public_html/gulfcans/images/bulk_images/files/werowerabejolaxenis.pdf
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1606dd8a8e08e7---govupepurirugeneso.pdf
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/cdd0c935a82556b23ddff81b0dd4dcd2/magolebeganawakesekit.pdf
    • http://abwmercury.com/uploads/files/12349601153.pdf
    • https://www.projectorrentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083f745e4e05---kenebiwilaguraduzovuza.pdf
    • https://bodwellassociates.com/wp-content/plugins/super-forms/uploads/php/files/947ae0a023f3f49f0869591338b1c758/nikufujak.pdf
    • http://assushop.com/userfiles/assushop.com/file/2212154239.pdf
    • http://virtualcharityevents.com/vce_cake/files/files/61137283086.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BkSY9tpko7c/uplcv?utm_term=satellite+solar+power+system+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_off0000d4a1.bin
dbfa09f4b0ef12e94b3608b9438a78f7565527ce40fae36e5ade8e27a480fdee
pdf-font-stream PDF embedded font (sfnt) at offset 0xD4A1 10828 bytes
font_01_sfnt_off0000edae.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEDAE 16792 bytes
font_02_sfnt_off000105c0.bin
b3c658e7924f645f6ffbff13f60aa81001275b22f98907998d917ab64866f912
pdf-font-stream PDF embedded font (sfnt) at offset 0x105C0 18716 bytes