Malicious PDF — malware analysis report

Static analysis result for SHA-256 bd5f125394182a32…

MALICIOUS

PDF

91.3 KB Created: 2021-09-21 15:48:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 67c878fee81fc148ef26f58db7064ab9 SHA-1: 5d13de70c899470fda2239c65474bb045f9dcbe8 SHA-256: bd5f125394182a32b08043ef746372847733b332e92e27c5f34e7b071b6b191b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised websites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The `PDF_SEO_DISPOSABLE_LINK_FARM` and `PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM` heuristics indicate a deliberate attempt to obscure the final malicious destination through multiple redirects and compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://krisoc.ru/uplcv?utm_term=expensive+bloxburg+houses PDF link annotation
    • https://ruxthai.com/ckfinder/userfiles/files/sonajimidovewo.pdfIn PDF document text
    • http://epmachine.ru/d/files/nusofagetimijejorexama.pdfIn PDF document text
    • http://www.pattyn360.com/upload/forum/files/toxamasirosili.pdfIn PDF document text
    • http://meruzhankhachatryan.com/app/webroot/files/file/23648048000.pdfIn PDF document text
    • https://www.verimevzabavu.cz/ckfinder/userfiles/files/3805377878.pdfIn PDF document text
    • http://studiolorenzino.eu/userfiles/files/zixodiwimadewu.pdfIn PDF document text
    • https://senarathgroup.lk/assets/media/file/xikomojovuwajuzigaj.pdfIn PDF document text
    • https://vegastel.eu/components/com_mijoshop/opencart/image/data/files/78591990863.pdfIn PDF document text
    • http://studiobaliva.eu/userfiles/files/26582866783.pdfIn PDF document text
    • https://herfection.herfection.tw/upload/ckfinder_temp/files/20210904015447.pdfIn PDF document text
    • http://liyangah.com/Upload/file/dirijenogafoguwa.pdfIn PDF document text
    • https://cylinder96.ru/admin/ckfinder/userfiles/files/21554956442.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/16131b221526f7---13018221973.pdfIn PDF document text
    • http://jor-agric-aqua.com/user_img/files/46505446155.pdfIn PDF document text
    • https://ballestermultiservicios.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137910b14ea4---6661401627.pdfIn PDF document text
    • http://delve-cr.com/uploads/naduviwebefediwiwumu.pdfIn PDF document text
    • http://studiotecnicomancini.eu/userfiles/files/jabuz.pdfIn PDF document text
    • https://www.lorenzofranzone.it/wp-content/plugins/super-forms/uploads/php/files/dc4a76ac11bb047d57588928deb878a0/45835034510.pdfIn PDF document text
    • https://saatyapi.com/upload/ckfinder/files/pagevukumubenumosovapona.pdfIn PDF document text
    • http://jingyitech.com/uploadfile/rosujuzosu.pdfIn PDF document text
    • http://vipacademy.org/userfiles/file/7234427237.pdfIn PDF document text
    • 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_off0000fd79.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFD79 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0001158b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1158B 18992 bytes
SHA-256: e45a27197364a3d4e73cae329314285df567492b4db34e7305d1846548c300a7
font_02_sfnt_off000147a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x147A0 10660 bytes
SHA-256: 02a96a7754e86272d4e279981948c3088efaad7f9d24581639cb933b243e3945