Malicious PDF — malware analysis report

Static analysis result for SHA-256 31b67160fc8d17a1…

MALICIOUS

PDF

79.7 KB Created: 2021-09-07 08:19:31 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 8a0a6218671170fc9b0de666433832ce SHA-1: 0c4a7ad4331e30428ad64589cf1d4af97b425536 SHA-256: 31b67160fc8d17a1953d00e1b0f5dfd8127c5b9fb390bd0e5b108bd46d692a9a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file contains numerous embedded URLs, many of which point to compromised CMS uploads and disposable hosting, indicating a link farm designed for phishing or malware distribution. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were directly extracted, the structure and URL patterns are consistent with a phishing lure, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/346a0c18b4879d44e9db2460605d63c0/56374310785.pdf In PDF document text
    • https://mmszke.hu/files/file/negiresub.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160e21c0a06b3a---ponekitegexu.pdfIn PDF document text
    • http://chromavials.com/d/files/rewurejarafozipisor.pdfIn PDF document text
    • http://jar-ted.pl/file/tirivuzuxerererelud.pdfIn PDF document text
    • http://mea-travel.pl/userfiles/file/kijodigopalone.pdfIn PDF document text
    • http://mobilenmr.com/files/files/39880846782.pdfIn PDF document text
    • http://subventionsbetrug.de/wp-content/plugins/super-forms/uploads/php/files/dc1qgrd7d7i3g7aue3td0592jr/kojera.pdfIn PDF document text
    • http://windcampus.com/wp-content/plugins/formcraft/file-upload/server/content/files/16074b2d4e8ace---kutonozagawawuxorenuz.pdfIn PDF document text
    • http://www.andreapondika.cz/file/90905448790.pdfIn PDF document text
    • http://recamonde.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160765b22e39df---fudefejuleluzer.pdfIn PDF document text
    • https://backcountryplayground.com/wp-content/plugins/super-forms/uploads/php/files/c65b9ab3798188a87f7a4f654dac4f02/94870875281.pdfIn PDF document text
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160a9820662f22---pulitawomaroxegaletagokuz.pdfIn PDF document text
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/1607216f955e42---kinaz.pdfIn PDF document text
    • http://flatadministration.com/uploades/fckeditorfile/30461617537.pdfIn PDF document text
    • https://accesoriosalmayor.com/images/userfiles/file/jiropejub.pdfIn PDF document text
    • http://kleiberit.ru/files/file/getedej.pdfIn PDF document text
    • https://ratsimae.ee/media/contents/file/memalejorevarifogelegu.pdfIn PDF document text
    • http://immodraft.nrw/images/architekten_agentur_images_/file/vagesed.pdfIn PDF document text
    • https://xn--78-6kce7dfhb9dwb.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/054d991fa27a1ad336afeb968300193a/darobimaleviwovej.pdfIn PDF document text
    • http://saydersan.com/firma/files/rigabiwa.pdfIn PDF document text
    • https://antoinepanau.com/wp-content/plugins/super-forms/uploads/php/files/6666d9fd4fdc01176816da4d9c40989a/9431118233.pdfIn PDF document text
    • http://navigator-33.ru/media/file/rinifinizotowanoti.pdfIn PDF document text
    • https://consurs.ro/ckfinder/userfiles/files/dolis.pdfIn PDF document text
    • http://ahxxzx.com/userfiles/202105/file/80839180364.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=conjuntos+iguales+pdfPDF 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_off0000c9fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC9FB 10832 bytes
SHA-256: f49998a647203427bc5fab9be2264149476be6426e2f6da58c45f4bf34da9299
font_01_sfnt_off0000e2e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2E8 21416 bytes
SHA-256: d5d7568f07a3080ae54639e4118c0a8bb37508569a5e53bf9e76d1e78eb48346
font_02_sfnt_off00011800.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11800 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1