Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3afb1e002a16e50…

MALICIOUS

PDF

73.0 KB Created: 2021-09-18 08:56:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: b30aba41aadc434537e8d877ac4d0432 SHA-1: d1c6afec052ac7e7e1becc048b97d4a70d843d8b SHA-256: a3afb1e002a16e50a2e9914e02c584cb9fe2ec565f473f5d4486e63565ae0ad7
126 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. It contains numerous embedded URLs pointing to various domains, suggesting a link farm designed to redirect users to potentially malicious content. The presence of PDF_SEO_DISPOSABLE_LINK_FARM heuristic further supports this, indicating a tactic to obscure the true destination. No scripts were extracted, but the overall structure and heuristics point to a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://catamma.ru/uplcv?utm_term=great+music+download+apps+for+android PDF link annotation
    • http://thingsantiquesla.com/userfiles/files/muxutobuwugizujukos.pdfIn PDF document text
    • http://ekotop.eu/userfiles/file/92916852600.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139b208440e1---sabowatato.pdfIn PDF document text
    • http://nitecoreromania.ro/files/file/mafifozomekorekudutozu.pdfIn PDF document text
    • http://annassteen.com/ckfinder/userfiles/files/zanujagewokopojojuve.pdfIn PDF document text
    • http://hepiran.com/cache/fck_files/file/30756320236.pdfIn PDF document text
    • https://birotex.rs/images/files/54838810475.pdfIn PDF document text
    • https://andhimazhai.com/images/files/tetanugonanapuje.pdfIn PDF document text
    • https://www.northamericatalk.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614261267aed2---87957480341.pdfIn PDF document text
    • https://www.thic.net/plugin/ce1/ckfinder/userfiles/files/10897520738.pdfIn PDF document text
    • http://studiofantino.it/userfiles/files/figagukezafivuvetixi.pdfIn PDF document text
    • https://art4you.sk/editor_uploads/system/files/69606438330.pdfIn PDF document text
    • http://standdominica.org/files/files/rixexide.pdfIn PDF document text
    • http://niengrangchuyensau.com/upload/contentFile/file/turotureronege.pdfIn PDF document text
    • http://studiozammuner.eu/userfiles/files/10027086283.pdfIn PDF document text
    • https://areopag.ru/sites/default/files/uploads/pukuvilivobufafepulikikab.pdfIn PDF document text
    • http://himalayakebab.com/shipinc/userfiles/files/zitesojun.pdfIn PDF document text
    • http://daiichigroup.net/uploads/news_file/19681477015.pdfIn PDF document text
    • http://www.astmalek.cz/obrazky/file/78881730286.pdfIn PDF document text
    • https://simpangkanan.com/contents/files/36697336951.pdfIn PDF document text
    • http://interroadholland.nl/userfiles/file/jawogulijidez.pdfIn PDF document text
    • http://lexuspolymers.com/assets/ckfinder/userfiles/files/zifefeveferaxokow.pdfIn PDF document text
    • https://csp-pub.com/stockages/files/92132073291.pdfIn PDF document text
    • http://christ-china.com/filespath/files/20210910182152.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_off0000ba6b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA6B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d27d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD27D 16472 bytes
SHA-256: 3cb248f3d7b203115ddedd8356c654efd6630bdb2f2073465228aa16b042bbdb
font_02_sfnt_off0000fc86.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC86 11004 bytes
SHA-256: 22426088d0fbbbadabf1ba3b7f45eb0d7f3515e1162dd5e07a6d13f521f16749