Malicious PDF — malware analysis report

Static analysis result for SHA-256 39c3829d5d4d2ced…

MALICIOUS

PDF

82.1 KB Created: 2021-01-21 22:02:06 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-15
MD5: 39187a99c0e51c908eadc8ba59514669 SHA-1: ddf6a3ba874838f86c8b2c50428b06108a80bd94 SHA-256: 39c3829d5d4d2ced76267f73d32c5612e94290a4d1e09747a459a0bafb9fc082
126 Risk Score
Tags
free-cdn-ebook-manual-lure

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs pointing to disposable hosting, characteristic of a link farm designed to redirect users. The document body, though heavily obfuscated, suggests a lure for a 'free download', likely to facilitate the download of a secondary payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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 https://trafffe.ru/123?utm_term=arabic+english+dictionary+pdf+free+download PDF link annotation
    • https://site-1196438.mozfiles.com/files/1196438/ios_audiotoolbox_example.pdfIn PDF document text
    • https://cdn.sqhk.co/gifexajed/uhihaib/30784922728.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4406229/normal_5fdabf05808c8.pdfIn PDF document text
    • https://site-1166621.mozfiles.com/files/1166621/melewuzubanusuvog.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4452382/normal_6009823042e99.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4416504/normal_6002c9529908e.pdfIn PDF document text
    • https://cdn.sqhk.co/xexisini/hje4gfo/spanish_civil_war_1936_map.pdfIn PDF document text
    • https://cdn.sqhk.co/dirujigowag/fjhTRjH/27524945729.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4450340/normal_5ff1789266cdf.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4369509/normal_5fd34075accee.pdfIn PDF document text
    • http://dilurijarejo.22web.org/general_dentist_cv_template.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4445742/normal_5ff16aab4011a.pdfIn PDF document text
    • http://nusururak.22web.org/bushnell_laser_boresighter_manual.pdfIn PDF document text
    • https://site-1171500.mozfiles.com/files/1171500/75238045878.pdfIn PDF document text
    • https://cdn.sqhk.co/kisibijobu/mJgihaD/gbc._emu_1._5._42_apk.pdfIn PDF document text
    • https://site-1176380.mozfiles.com/files/1176380/36920253747.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4464077/normal_5fcdafcba63e8.pdfIn PDF document text
    • https://cdn.sqhk.co/kikolibub/u2jiNhf/daily_forklift_inspection_checklist_excel.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://najorenowodume.epizy.com/bromhidrosis_axilar_tratamiento.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
    • http://scripts.sil.org/OFLIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
stream_004_off00010a9d.bin decompressed-pdf-stream PDF FlateDecoded stream at offset 0x10A9D 26612 bytes
SHA-256: a20e1a866d9b9c271a1ccdc941ca782d4c6b155710dc8ffd0f48e17c18f1e5ad
font_00_sfnt_off0000d40a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD40A 5740 bytes
SHA-256: adf7bd61e9dbfb24b618f81b88fb41fe33583d25b935b947630354c14c857065
font_01_sfnt_off0000e79a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE79A 10244 bytes
SHA-256: 4ee4b32cbfca126d92d57fd13c527529832475e078cd7247bc7442aea5f01084

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