Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1b6577ba0b017aa…

MALICIOUS

PDF

89.5 KB Created: 2021-07-03 02:12:48 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-08-20
MD5: b675361d3ae3b0223dbacf8130921c44 SHA-1: 119a2895017dc110b3f5efaddc14b0ea2678c300 SHA-256: c1b6577ba0b017aa8f7ded9207b82a1d96d584e0126e5b796e790ebc833e7493
104 Risk Score

Malware Insights

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

The sample is identified as malicious by an ML classifier and exhibits characteristics of a link farm, with numerous embedded URLs pointing to compromised WordPress sites and disposable domains. The presence of a 'download button' heuristic suggests a lure to entice users to click these links. While no scripts were extracted, the structure and URL patterns indicate an attempt to redirect users, potentially for SEO abuse or to serve further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://mindspacepsytherapy.com/upload/ckfinder_temp/files/20210703054428.pdf In PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080c86082621---23170221384.pdfIn PDF document text
    • https://www.mysmilestudios.com/wp-content/plugins/super-forms/uploads/php/files/16e208734e7e8f7f2dd447e4bc36bdba/kejakikodefove.pdfIn PDF document text
    • http://kameleonhastanc.hu/files/file/87117405132.pdfIn PDF document text
    • https://ventana-sur.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608a6a3bd3c31.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b04f5651c13---11709131790.pdfIn PDF document text
    • https://www.dolphinrfid.com/wp-content/plugins/formcraft/file-upload/server/content/files/16089a515251e3---52923749973.pdfIn PDF document text
    • http://africanhairbraidingsalon.com/userfiles/file/94532381527.pdfIn PDF document text
    • https://purefeeling8.com/data/file/25109361356.pdfIn PDF document text
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/ddc96103985332b314fb2ca1aa371711/61684442261.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160cb01e08b133---12371597725.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8495bb0c12---wuresideziruwe.pdfIn PDF document text
    • http://www.petersmetalstitching.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160aec2930522b---72860864746.pdfIn PDF document text
    • https://esprimagroup.com/userfiles/file/zodujilupibexawurojizo.pdfIn PDF document text
    • https://xn--nmqu14inmf.com/upload/files/18457199504.pdfIn PDF document text
    • https://xn-----6kcabagcgfjsxjciriy6alkh6a7aqk.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/3bf8e63c1b32231ec101548bc943f6bc/jividavivuwodanofuwumikeb.pdfIn PDF document text
    • http://www.holzbau-hoelzl.at/wp-content/plugins/formcraft/file-upload/server/content/files/160b354e1820d1---24514199582.pdfIn PDF document text
    • http://kientrucnhacuagio.com/upload/files/vediladojodazemuko.pdfIn PDF document text
    • https://www.clubmanizales.com.co/wp-content/plugins/formcraft/file-upload/server/content/files/1609549ae45b18---96141327112.pdfIn PDF document text
    • https://www.sidertest.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c727d68a2b3---tarefanix.pdfIn PDF document text
    • https://alpinismbihor.ro/app/webroot/files/userfiles/files/febuvam.pdfIn PDF document text
    • https://duext.com/wp-content/plugins/super-forms/uploads/php/files/f70f3d21c53a0771c692351327397937/vaxodigoribuxa.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/9236b7c1137a4493490901d350177896/luvafegoloxazabidadufo.pdfIn PDF document text
    • http://pocatellocampfire.com/wp-content/plugins/super-forms/uploads/php/files/3njs1k1b5knhkkinolvpat780q/8150729890.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=fallout+who+started+the+great+warPDF 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_off0000f963.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF963 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001117a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1117A 10492 bytes
SHA-256: bcef7ca7f10f44b9a878782892fa1506d9cd9b6a7fce5275eca4559194e50fb7
font_02_sfnt_off0001295b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1295B 17404 bytes
SHA-256: b88d14d0ac7f238faf857f24ee4d337b3d6d802a427223062370dec23d715d39