Malicious PDF — malware analysis report

Static analysis result for SHA-256 23b1bc293ee33a13…

MALICIOUS

PDF

81.9 KB Created: 2021-08-08 02:46:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: aab04e270d11905a198794a98959e76b SHA-1: 31d18453f6f1b4fe0d60885c935e35d891dd85fc SHA-256: 23b1bc293ee33a132c6e0e0ad879cfc1d69db98ca6cd25f6a4f67d4c7c9d785e
156 Risk Score

Malware Insights

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

The file is identified as malicious by ML classifiers and ClamAV, with multiple heuristics indicating it functions as a link farm hosted on compromised WordPress sites. The embedded URLs point to various PDF files on these compromised domains, suggesting a redirection chain designed to lead users to malicious content. No scripts were extracted, and the document body was unreadable, limiting further analysis of the specific payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1606e93d6de928---kuxofekufelekufewefe.pdf In PDF document text
    • https://spacio.hk/attachment/file/38905498597.pdfIn PDF document text
    • https://thinkhigh-tech.com/d/files/13852621281.pdfIn PDF document text
    • http://df-2.de/images/daten/file/daxomuzezit.pdfIn PDF document text
    • https://afd.me.uk/wp-content/plugins/super-forms/uploads/php/files/mftagf36l4m9iucob38401vgg9/65522221162.pdfIn PDF document text
    • https://cutletsmeat.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c0aabf1d9b7---duvunipi.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/h7e59rgucbj0t80io6656v71g2/fowevewexiredu.pdfIn PDF document text
    • https://creationstationdance.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a640ad118fa---jepijotimejowe.pdfIn PDF document text
    • http://ort168.com/upload//ckeditor/files/sedovuvad.pdfIn PDF document text
    • https://bojovicsirogojno.com//files/38088905824.pdfIn PDF document text
    • http://royalgoodviewresort.com/Uploads/file/xixejelumoxofumevetorupum.pdfIn PDF document text
    • https://faceless.me/userfiles/files/suvanadakokotezutenogud.pdfIn PDF document text
    • http://duepassidalcentro.it/userfiles/files/10453339812.pdfIn PDF document text
    • http://ipceurope.eu/assets/file/geborokozorapojifoziso.pdfIn PDF document text
    • http://watthaistuttgart.de/userfiles/file/54798126624.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609f66e6e3f77---vakelabevisipufirizexit.pdfIn PDF document text
    • http://mp-hd.de/data/aktualnosci_imgs/file/71796850289.pdfIn PDF document text
    • https://orkhaconstruction.com/wp-content/plugins/super-forms/uploads/php/files/fdo2ci488oo73idlh6435f8t6h/37817322470.pdfIn PDF document text
    • https://www.gryf-wet.pl/ckfinder/userfiles/files/zulutatavonovumesi.pdfIn PDF document text
    • http://aclamerica.com/customers/CMS-IMAGES/file/28391184402.pdfIn PDF document text
    • https://rffsev.ru/wp-content/plugins/super-forms/uploads/php/files/fa0dac7b1445f01129796cc3c020bc58/zisozep.pdfIn PDF document text
    • http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc4b00b0635---25675906867.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=epi+calculator+sample+sizePDF 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_off0000dabc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDABC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f2ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF2CE 17552 bytes
SHA-256: d50d0bc53f2c557fc333887f9bc740617c21fc9da0a270fa610d954583212cbc
font_02_sfnt_off00012180.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12180 10576 bytes
SHA-256: a85dff0e12598b503f8f2ea40f9e2b3a13507d8d80aad900c30bab8fb083943f