Malicious PDF — malware analysis report

Static analysis result for SHA-256 b53cbd826ba2dc2f…

MALICIOUS

PDF

85.6 KB Created: 2021-07-06 13:34:05 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7f7c675203a37718c23c068e4e68d5c9 SHA-1: 9c63f3f020bc51dadf959b7d0c9ce4e4104e21a6 SHA-256: b53cbd826ba2dc2f9e05d577d0c358fee429d46c2ad8682a7bbfef73ace3e084
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links to external websites, many of which appear to be hosted on compromised WordPress sites or disposable domains, suggesting a link farm for phishing or malware distribution. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were explicitly extracted, the presence of numerous URLs and the nature of the heuristics point towards a phishing or scam campaign designed to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://smidgel.ru/uplcv?utm_term=target+high+book+download
    • https://stellabakingcompany.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e3e52d3a45---44741149494.pdf
    • http://vladjurnalist.ru/archive/file/nuwiponopaxerekorisir.pdf
    • http://starwindows.ie/ckfinder/userfiles/files/kasurefipikelixizi.pdf
    • http://giga.sk/storage/file/zepezazobuxisaxaxuxulilod.pdf
    • http://biondiairsystem.it/userfiles/files/62022153101.pdf
    • http://www.jhannahs.com/wp-content/plugins/formcraft/file-upload/server/content/files/160df480b6a675---10274111480.pdf
    • https://www.sblending.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/16073dbc30fc2e---gotumelekigo.pdf
    • http://www.marsagri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ff7975aa0b---zukobazufupofawinaxebix.pdf
    • http://glina-master.ru/admin/ckfinder/userfiles/files/livopakobinazukiwusike.pdf
    • https://amalighting.com/wp-content/plugins/super-forms/uploads/php/files/cd1c2d61b4ac6527e1abda4586143eda/lofopumatat.pdf
    • http://charivne.info/images/file/pekojunirogir.pdf
    • https://www.dartmusicfestival.co.uk/wp-content/plugins/super-forms/uploads/php/files/9d4d7752f32c73165aec332bd741b25e/sudobezenem.pdf
    • http://www.commandinglife.com/wp-content/plugins/formcraft/file-upload/server/content/files/160abddcd6899d---83560652261.pdf
    • https://xn--1--8kcai1ck2bs.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/bde7882c59cff73ed6a5f7018f4ee726/zunujob.pdf
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/160ae8a4aadc95---10298218643.pdf
    • https://www.keystonecare.co.uk/wp-content/plugins/super-forms/uploads/php/files/b71648d293b1c6165a1603b6fddd7126/besivazufokuxisureles.pdf
    • https://event-connections.net/wp-content/plugins/formcraft/file-upload/server/content/files/1606d173d0f073---9823180249.pdf
    • https://acgroupenterprise.com/userfiles/file/99175540501.pdf
    • https://alfa-pechati.ru/wp-content/plugins/super-forms/uploads/php/files/a30d1e457f16421ff96c9b27d2b674ac/divazaxofixikimemunimaka.pdf
    • http://cctechlaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/tuxotelinofov.pdf
    • https://www.elektrobetrieb-scholz.de/wp-content/plugins/formcraft/file-upload/server/content/files/16073feafd447c---lexisa.pdf
    • https://www.amiunaorchestra.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1608757b602b02---levemuj.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_off0000ece9.bin
d5e9d51cf6bebdaf4dcf59d59d635268f135881aa74e60dac534356c0fe1bcab
pdf-font-stream PDF embedded font (sfnt) at offset 0xECE9 16848 bytes
font_01_sfnt_off0001190e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1190E 16792 bytes
font_02_sfnt_off00013125.bin
531e7fe8a18996c9ae6c2d79fcde93b1959ce318a0e73a9ee6bce7cdbc3bcdec
pdf-font-stream PDF embedded font (sfnt) at offset 0x13125 10640 bytes