Malicious PDF — malware analysis report

Static analysis result for SHA-256 d5900d5ef9d391dd…

MALICIOUS

PDF

71.6 KB Created: 2021-09-24 15:13:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 0e09d1735eae2befc711d03b933ec000 SHA-1: 81c988e59d6149bc4ed89af4849ca135ac8c58e9 SHA-256: d5900d5ef9d391dd1ef0335136b3bb3ef22a4a4f56117468842c75d903e41e9f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple compromised or disposable hosting sites. While no scripts were explicitly extracted, the nature of PDF-based link farms often involves embedded JavaScript to facilitate redirection, hence the inclusion of T1059.007.

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://elsadaulte.com/ckfinder/userfiles/files/sojij.pdf In PDF document text
    • http://sswjeans.com/files/55766969356.pdfIn PDF document text
    • https://observatoire-omic.org/documents/file/gupukulilojazazuj.pdfIn PDF document text
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613fc7eabb41b---21907045629.pdfIn PDF document text
    • http://sweatrinserepeat.com/ckfinder/userfiles/files/22043163601.pdfIn PDF document text
    • http://nhungbaithuocnam.com/img-tvdl/files/13544873194.pdfIn PDF document text
    • http://cuacuonanbinh.com/userfiles/file/gibex.pdfIn PDF document text
    • http://www.fred-robin.com/ckfinder/userfiles/files/44982385801.pdfIn PDF document text
    • http://ordineveterinarireggioemilia.it/userfiles/files/jepoluregedafuw.pdfIn PDF document text
    • http://fgsconsulta.com.br/ckfinder/uploads/userfiles/files/ritimutonifalujosa.pdfIn PDF document text
    • http://www.ondebiz.com/userfiles/file/nadakejuzaduweki.pdfIn PDF document text
    • http://nguyenxuanhuong.com/upload/files/jiwisuge.pdfIn PDF document text
    • https://habibitoursegypt.com/ckfinder/userfiles/files/nolewuwetivejowopavesigod.pdfIn PDF document text
    • http://didopack.com/files/4005300513.pdfIn PDF document text
    • http://gbfrjournal.org/pds/userfiles/files/92544675358.pdfIn PDF document text
    • https://dutchfansitenetwork.nl/ckfinder/userfiles/files/33126084570.pdfIn PDF document text
    • http://inbiosa.eu/static/cfiles/files/98390595853.pdfIn PDF document text
    • https://ssmahavidyalaya.org/lion/uploadedfiles/fck/files/file/fatizifadivivaxokegedo.pdfIn PDF document text
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/16133c5c8c38cd---47693766154.pdfIn PDF document text
    • http://tydafa.com/dafa/uploadfiles/20210918232753.pdfIn PDF document text
    • http://www.marcelasemper.com/wp-content/plugins/formcraft/file-upload/server/content/files/16131ffdb9728f---xogonitonejikesisap.pdfIn PDF document text
    • https://autoroman-service.ro/imagini_ws/79774222312.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=free+unused+fortnite+codesPDF 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_off0000b349.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB349 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cb5b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB5B 17792 bytes
SHA-256: b31db958c9d4b821fe81a7317ae562dbcd56e99a3855d1100cd1677c4cceda55
font_02_sfnt_off0000f924.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF924 10340 bytes
SHA-256: f8e8473c8aaf9e0e5c3bc96baca2b4ab323083c2938d8e16a735ffec63163bf8