Malicious PDF — malware analysis report

Static analysis result for SHA-256 b757792ffb7ca4d7…

MALICIOUS

PDF

107.2 KB Created: 2021-09-24 06:25:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: b7bd9ceec3f04a401d18c448e69621bf SHA-1: fe6ae57ec6c90813e6a171e89096cae29d2a293e SHA-256: b757792ffb7ca4d7e816633225bc3bd1036b1f3c34e19398986004d1f033ccb6
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The PDF contains numerous embedded URLs, with one heuristic identifying it as a link farm on disposable hosting. While no scripts were explicitly extracted, the presence of PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM heuristics suggests the document is designed to redirect users to potentially harmful external sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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 http://mg001.cn/upload_fck/file/2021-9-24/20210924071018521631.pdf In PDF document text
    • https://bhopalliteraturefestival.com/mpsdp/uploads/files/17189096452.pdfIn PDF document text
    • http://parcroyale.hk/userfiles/kaseluxetuzuma.pdfIn PDF document text
    • http://phutungtdc.com/upload/files/91177500590.pdfIn PDF document text
    • https://hatinhjobs.com/upload/files/39238070193.pdfIn PDF document text
    • http://adasbruiloften.nl/userfiles/file/48687368518.pdfIn PDF document text
    • https://marbeyoyun.com/calisma2/files/uploads/67313561717.pdfIn PDF document text
    • http://chinhsuasolieu.com/media/files/14054021572.pdfIn PDF document text
    • http://tdbm.vn/upload/files/dolunebapa.pdfIn PDF document text
    • http://tv-sat.cz/userfiles/file/59006097191.pdfIn PDF document text
    • https://pikewallis.no/wp-content/plugins/formcraft/file-upload/server/content/files/16143a74ab6efa---lumubogufuwiganupow.pdfIn PDF document text
    • http://spbi.cz/res/file/jeleruzatok.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614d40a451a96---rotonijivekojuredaraji.pdfIn PDF document text
    • http://yogaschoolofkerala.com/photos/editor/files/fogurarugiwuxoronu.pdfIn PDF document text
    • https://nacituran.com/userfiles/file/gogokuxalofanakizudalow.pdfIn PDF document text
    • http://datcat.vn/2018/file/10423183530.pdfIn PDF document text
    • http://usagimatur.com/files/others/71446506357.pdfIn PDF document text
    • http://sofia-es.tokyo/yamituki-n/uploads/files/xapovebuz.pdfIn PDF document text
    • http://fatfailogistics.com/fckeditor/files/file/14144080242.pdfIn PDF document text
    • http://studiomuraca.eu/userfiles/files/wubuxajexivosebege.pdfIn PDF document text
    • http://radiopoint.cz/userfiles/file/63663531406.pdfIn PDF document text
    • http://webmba.fr/client/logo/file/86876755654.pdfIn PDF document text
    • https://ruxthai-guesthouse-chiangmai.com/ckfinder/userfiles/files/42984780121.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=sonic+3+iosPDF 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_off00013a42.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13A42 9932 bytes
SHA-256: 866396f0d116c6e5fb42758f9a95a7bd46eb8fb0e5b2d5a51c917c3e90e3bd72
font_01_sfnt_off00015044.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x15044 20928 bytes
SHA-256: 5621dc1994b1581b8e1feb74078f6b1e67ec4d82a42ee9afc0a45ed41628f1d9
font_02_sfnt_off000187ce.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x187CE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1