Malicious PDF — malware analysis report

Static analysis result for SHA-256 8765a92ac323b40a…

MALICIOUS

PDF

88.2 KB Created: 2021-07-24 05:27:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 4f8ada8ebddb909f613811dad4557507 SHA-1: 40c4728f81fb0095b4793df4bbd1c0f3d4de3988 SHA-256: 8765a92ac323b40a1ce69ea8b8f732674a31f5975126710e79cdc92b7a393208
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous links pointing to compromised WordPress sites, which in turn host other PDF files. This pattern suggests a link farm designed to obscure the ultimate destination and potentially evade detection. The ClamAV detection and ML classifier strongly indicate malicious intent, likely related to phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://argentum.com/wp-content/plugins/super-forms/uploads/php/files/r1hbl09764u7sd1fqltib09d4l/zemos.pdf In PDF document text
    • http://ambvetfanini.eu/userfiles/files/jagokamumakojupikukiru.pdfIn PDF document text
    • https://envomask.com/wp-content/plugins/super-forms/uploads/php/files/e84218aa6c0699f48f44a7827e48b25c/69994353837.pdfIn PDF document text
    • https://atvatextile.com/upload/ckfinder/files/bulofedidojus.pdfIn PDF document text
    • http://banglenhospital.com/UserFiles/File/26766707874.pdfIn PDF document text
    • http://truhlarstvisollner.cz/data/file/62426322838.pdfIn PDF document text
    • http://www.reroofingbrisbaneqld.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/1609ead68b0e46---wemigudosod.pdfIn PDF document text
    • https://sayurhijau.com/contents//files/jonowoxojegep.pdfIn PDF document text
    • https://alatheir.com/atheirwsfiles/file/xekabixejukorukatomawiguf.pdfIn PDF document text
    • http://efuegypt.org/userfiles/file/97729591814.pdfIn PDF document text
    • http://jeugdopdewetenschapsagenda.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607b2c9b63023---fojekamem.pdfIn PDF document text
    • https://ip-pharma.net/data/files/75507519292.pdfIn PDF document text
    • http://learningkey.org/userfiles/86701136751.pdfIn PDF document text
    • http://kaplanpm.com/wp-content/plugins/formcraft/file-upload/server/content/files/160756c68c06f5---dadefubonagatomexoxipoxu.pdfIn PDF document text
    • http://tasteofruraleurope.eu/upload/File/50422329334.pdfIn PDF document text
    • http://www.gradur.ba/wp-content/plugins/formcraft/file-upload/server/content/files/160c4495f2a051---13249367258.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/xagaz.pdfIn PDF document text
    • https://zenkenmoshi.info/images/files/file/xumasawafigowolu.pdfIn PDF document text
    • https://sanxuattrucauthangkinh.com/Images_upload/files/28646296017.pdfIn PDF document text
    • https://drivetripper.com/userfiles2020/files/4744480487.pdfIn PDF document text
    • http://permianhighschool1970.com/clients/e/ef/efee9fcbc667252fc4b649c8163d3733/File/93633969263.pdfIn PDF document text
    • https://amezdigital.com/wp-content/plugins/super-forms/uploads/php/files/44e95d92d471c81454c1e2ab73174d94/zogijaxibinabarugosabi.pdfIn PDF document text
    • http://goodwynva.com/clients/d/de/de91e19d235d8a3764238851c6b73f99/File/33690039892.pdfIn PDF document text
    • https://www.charroninc.com/wp-content/plugins/super-forms/uploads/php/files/fc110e668f194b22950630210b4c3ce4/50839978210.pdfIn PDF document text
    • http://aeskulap24h.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c61aaf859f5---julosus.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=ver+telenovelas+y+series+gratis+online+en+hd+darkillerPDF 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_off0000f700.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF700 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010f17.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F17 10768 bytes
SHA-256: f0bdfc6d801aca1335c6882949b9b3d85c65165c428770120d2a83b237f245c9
font_02_sfnt_off0001279c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1279C 16424 bytes
SHA-256: 6e36088c0febfc8b46e26eec08650cdc43299bd61d0962c43185b7434ba2303c