Malicious PDF — malware analysis report

Static analysis result for SHA-256 817afc515d1ba0f1…

MALICIOUS

PDF

82.9 KB Created: 2021-10-06 20:53:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-03
MD5: 9b3621e2f4a5c1fdb6fa1eb015140ca2 SHA-1: 8a7bb0d286455e6bd900c26ed433adf52f941f51 SHA-256: 817afc515d1ba0f17a53d898960b016ab068b8c30ede0c48eb956deca1c41545
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is identified as malicious by ML classifiers and ClamAV, specifically as a phishing trojan. It contains a large number of embedded URLs pointing to various domains, suggesting a link farm or phishing campaign. The PDF_SEO_DISPOSABLE_LINK_FARM heuristic indicates a strategy of using many distinct hosts with few links per host, a common tactic for evading detection. No scripts were extracted, but the primary attack pattern involves directing users to external, potentially malicious, websites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://cructi.ru/uplcv?utm_term=the+working+model PDF link annotation
    • http://labradory.pl/file/68677673526.pdfIn PDF document text
    • http://www.cerel.eu/images/wyswig_images/file/50664152193.pdfIn PDF document text
    • http://bowlingkillers.com/imgdb/files/48411262961.pdfIn PDF document text
    • http://big-blue-bus.com/pics/fotos/1/file/35508513310.pdfIn PDF document text
    • https://asiapharma.la/files/files/vubulikekinamekolet.pdfIn PDF document text
    • https://vwb.mrv-educationservices.com/content_file/files/60276990028.pdfIn PDF document text
    • http://benthanhsgfarm.com/images/uploads/files/pasebikevulo.pdfIn PDF document text
    • https://mclandpin.com/calisma2/files/uploads/mokurolamo.pdfIn PDF document text
    • http://codemessaging.net/ckfinder/userfiles/files/53113326443.pdfIn PDF document text
    • https://imagebuzz.net/ckfinder/userfiles/files/93942224937.pdfIn PDF document text
    • http://ctm.it/userfiles/file/18218179902.pdfIn PDF document text
    • http://kenhuffbuilders.com/userfiles/file/34368969670.pdfIn PDF document text
    • https://mallncart.com/userfiles/files/fobuvutamagoso.pdfIn PDF document text
    • http://vanguardhungary.hu/userfiles/file/99347658096.pdfIn PDF document text
    • http://auvergne.annuaire-regional.com/ckfinder/userfiles/files/85865889811.pdfIn PDF document text
    • http://mutitar.com/user_img/files/susapowolimigopixerefi.pdfIn PDF document text
    • https://www.bevillelecomte.com/ckfinder/userfiles/files/fafafaj.pdfIn PDF document text
    • http://proficlim.ru/public/userfiles/file/78378997662.pdfIn PDF document text
    • https://blugarden.eu/file/rotupagivazaxanuki.pdfIn PDF document text
    • http://2sisaccount.com/userfiles/files/mazodutufeza.pdfIn PDF document text
    • https://coffotea.com/uploads/files/202109271707555933.pdfIn PDF document text
    • https://sandalyecenneti.com/wp-content/plugins/super-forms/uploads/php/files/0ol2t4b2p96t3cf1i623l8243q/pazefejonoferixekudojeso.pdfIn PDF document text
    • http://fisioterapiasuzzara.it/userfiles/files/wazukuwudewoj.pdfIn PDF document text
    • http://drapikowski.pl/uploaded/fck_files/file/11800765003.pdfIn PDF document text
    • http://louisiana-arts.org.s150269.gridserver.com/siteuploads/editorimg/file/16363233289.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_off0000e28d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE28D 10408 bytes
SHA-256: 3671f68fae4bee7472e9fbd39fa1e846b3d5fe34c833e41d732129b135ecb7bc
font_01_sfnt_off0000f9ae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF9AE 17324 bytes
SHA-256: 7c6fc16b815fd05f40d3b3ddd33bc88a6a54f26b669a29c603ee18392f625e4f
font_02_sfnt_off00012670.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12670 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1