Malicious PDF — malware analysis report

Static analysis result for SHA-256 83b1e80a8107c737…

MALICIOUS

PDF

81.8 KB Created: 2021-07-04 00:21:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3d2f5dc7e43635688334f0e72cafb3e2 SHA-1: 29688876c035f28122719b3d099154a8bdc27152 SHA-256: 83b1e80a8107c73765bf1f5f125a1b8c5d5e5a189eb4614867827d7970dd1c26
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous links, many pointing to compromised WordPress installations, suggesting a link farm used for distributing malicious content or phishing. The ML classifier and ClamAV detection strongly indicate malicious intent. Although no scripts were directly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

Heuristics 7

  • 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.
  • Urgency / deadline lure low SE_URGENCY_LURE
    Document contains urgency or deadline language ('account will be terminated', 'action required within 24 hours', etc.) — useful context, but low-signal without other findings
  • 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://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/160822e9cbd88a---46936482714.pdf
    • http://werkkledingverkoop.nl/images/docman/files/85071956023.pdf
    • https://holzhaus-suedtirol.it/wp-content/plugins/formcraft/file-upload/server/content/files/16071902cdb02b---77925320826.pdf
    • https://svetpoznaniyaonline.ru/wp-content/plugins/super-forms/uploads/php/files/fddf0fcd01b2be52ec01e5bb5804eea3/wekomupowelukasonivini.pdf
    • http://www.viksexteriors.com/wp-content/plugins/formcraft/file-upload/server/content/files/16095a20832a8c---92165819269.pdf
    • https://macleanpinesdrivingschool.com.au/wp-content/plugins/super-forms/uploads/php/files/0746b6beef573dd65f5e9e7c20632cc2/pexamevimataz.pdf
    • https://www.ediliziaindustriale.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bcf1fbd0de---xejuvarax.pdf
    • http://dmhu.eu/uploads/uplib/file/siroj.pdf
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b76c9a7367e---38003135122.pdf
    • http://takeacode.net/user/d41d8cd98f00b204e9800998ecf8427e/file/kobisokejef.pdf
    • http://vdgairconditioning.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16083910dbf0a5---13306632919.pdf
    • https://controlcert.se/wp-content/plugins/formcraft/file-upload/server/content/files/160874cac4b611---gobekujubevewaridi.pdf
    • https://barcelonamedicalcenter.com/files/galeria/files/gelov.pdf
    • http://www.hkqi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a5a59ebf0c6---gowisixixisozikoni.pdf
    • http://alexanderkanevskyartistbiography.com/clientMedia/file/1806043155.pdf
    • http://woonhuislift.info/wp-content/plugins/formcraft/file-upload/server/content/files/160d8e31baa460---72725161336.pdf
    • http://szkolka-wiercioch.pl/files/file/77767489120.pdf
    • https://ruiguoex.com/upfile/files/2021/06/04/73883870902.pdf
    • http://smithmurdock.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607eeeb43e37d---xalibutufiwev.pdf
    • http://przychodnia-felinskiego.pl/uploads/editor/file/pokivas.pdf
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/47cf5727d47ecdce8dde6444bae006f5/zumula.pdf
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/1609eca4b27b7c---nebigajujisinosaradezi.pdf
    • http://beta-rc.com/upload/files/fafofusopanejujejin.pdf
    • https://ambient-interier.cz/files/files/wewedilapedubuzixi.pdf
    • http://atonoserver.com/userfiles/file/53628652830.pdf
    • https://primewestelectrical.com/wp-content/plugins/super-forms/uploads/php/files/c50f1cefdc1f52c993e1fd1e1db23590/zemexawusufomabujababi.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=applications+of+gis+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_off0000ddc1.bin
8336e9018e3675c82e022a63f722350e8e9e38d94dc4825441003dd30e4b35fa
pdf-font-stream PDF embedded font (sfnt) at offset 0xDDC1 17036 bytes
font_01_sfnt_off00010a1c.bin
917f3ddf01796ebc21a3539a2299fa25dc75e0ed054d030591662f9b83722887
pdf-font-stream PDF embedded font (sfnt) at offset 0x10A1C 10544 bytes
font_02_sfnt_off0001221c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1221C 16792 bytes