Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4a0a384998213a4…

MALICIOUS

PDF

88.2 KB Created: 2021-06-30 01:07:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: fd3245fe00b97d32b58b7803de371304 SHA-1: 0512af54d45fcb9df4e4cf069c5e5735e6178557 SHA-256: e4a0a384998213a4162ef89ee24f2f1dafcb2035c68ae0ff37e05f3cddde7e33
96 Risk Score

Malware Insights

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

The PDF file was identified as malicious by an ML classifier with high confidence. It contains numerous links, many pointing to compromised WordPress upload directories, suggesting a link farm or distribution point. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for direct user reading but rather as a container for these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • 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://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/709njbogo7gnnhcevl4p0tr95g/vowifelepugajefo.pdf In PDF document text
    • https://rockyshairsalon.com/wp-content/plugins/super-forms/uploads/php/files/cf7rvk14i62khcn9ghe684qidq/fovilopedo.pdfIn PDF document text
    • http://kristenpell.com/userfiles/files/17048810031.pdfIn PDF document text
    • https://advancedbusiness.co/wp-content/plugins/super-forms/uploads/php/files/d73c2b2992d3d1abe90f0eb3e03f0e5c/dapekuxeligo.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/96159311271.pdfIn PDF document text
    • http://suncitygroup.ir/basefile/suncitygroupir/files/39236310997.pdfIn PDF document text
    • https://vidolamerica.org/wp-content/plugins/super-forms/uploads/php/files/aa464641208fe1725f7fb0b89b64df93/89244017841.pdfIn PDF document text
    • http://sireny.net/share/files/roxigexedizaz.pdfIn PDF document text
    • https://gearforfree.com/wp-content/plugins/super-forms/uploads/php/files/qlbktr7v5l2luq3hrporh7bh6l/siwupo.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c7735b4c01a---33531909838.pdfIn PDF document text
    • https://acethamessecurity.co.uk/wp-content/plugins/super-forms/uploads/php/files/756e1c1cd8e8aa7805ff5154a49b9fdb/6634651559.pdfIn PDF document text
    • http://daimarconstrucciones.com/images/admin/file/wotilenuwutipusagukunikox.pdfIn PDF document text
    • https://csp-pub.com/stockages/files/zepiwoli.pdfIn PDF document text
    • http://cricalliance.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096262ec928e---24331809828.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1607df6b513192---romagikubigabivugexev.pdfIn PDF document text
    • http://flygarfield.net/userfiles/file/18682080837.pdfIn PDF document text
    • https://zlatartopalovic.rs//files/retitunurivoden.pdfIn PDF document text
    • http://consol.hu/images/uploadedimages/file/74838865299.pdfIn PDF document text
    • http://intergeored.com/upload/File/modud.pdfIn PDF document text
    • http://adaviestransportltd.com/userfiles/file/manezanoze.pdfIn PDF document text
    • http://thedigitalscorecard.com/userfiles/files/kojilokajinitafoga.pdfIn PDF document text
    • https://aimara-bg.com/userfiles/file/najugujaxozafojaxevagab.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/6naE_Nh8_CY/uplcv?utm_term=words+from+o+for+nurseryPDF 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_off0000f45d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF45D 10324 bytes
SHA-256: 772e5bde9a4f7012efac260a53700951f994210e2a106c81d00d07bffc78c959
font_01_sfnt_off00010ba3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BA3 18400 bytes
SHA-256: 6e6448e9d475d4184d363fda2a8c91333bc58e4a325824e34785d55e8c538608
font_02_sfnt_off00013bac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13BAC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1