Malicious PDF — malware analysis report

Static analysis result for SHA-256 8baf23f641666d11…

MALICIOUS

PDF

80.8 KB Created: 2021-10-14 16:29:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: dea7f4db8f01beafbd88c26184dcbbde SHA-1: 9bba23da11988b331f86e851ac393aeb142d45e1 SHA-256: 8baf23f641666d11a7899e3a00f28b3f1369e6bd40ae433742aa2b736bf81ef2
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous external links, many pointing to disposable hosting, and is flagged by ML classifiers and ClamAV as malicious. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' indicates a link farm strategy, suggesting the PDF's primary purpose is to redirect users to potentially malicious websites. While no scripts were explicitly extracted, the presence of embedded URLs and the overall structure strongly suggest a phishing or malware distribution vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://ketchas.ru/uplcv?utm_term=role+of+microbes+in+carbon+cycle+pdf PDF link annotation
    • http://banglenhospital.com/UserFiles/File/85719899158.pdfIn PDF document text
    • http://uzks.hr/upload/datoteke/lidafeforarabonevoberu.pdfIn PDF document text
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/161580563ae45b---227349195.pdfIn PDF document text
    • http://spellenindex.nl/images/uploads/zirive.pdfIn PDF document text
    • http://ettorebelfioreliutaio.it/userfiles/files/34183151645.pdfIn PDF document text
    • https://mashtalkandil.com/userfiles/file/28616168845.pdfIn PDF document text
    • http://nhatminhtrading.vn/app/webroot/uploads/files/45804011182.pdfIn PDF document text
    • https://luxm.pl/userfiles/file/zoxutag.pdfIn PDF document text
    • http://svaz-podnikani.cz/files/file/36339170334.pdfIn PDF document text
    • https://tradingcall.in/ckfinder/userfiles/files/tagowuxi.pdfIn PDF document text
    • https://panoramabyty.cz/content/24161454762.pdfIn PDF document text
    • https://evermoral.hk/upload/file/1632308847.pdfIn PDF document text
    • http://profitoolinfo.ru/ckfinder/userfiles/files/78560503797.pdfIn PDF document text
    • http://architettosbaffo.com/userfiles/files/99931789957.pdfIn PDF document text
    • http://sevoir.hu/uploads/file/18466537595.pdfIn PDF document text
    • http://noithatlekhanh.com/Images_upload/files/meverebadasow.pdfIn PDF document text
    • http://lilit-realty.com/wp-content/plugins/super-forms/uploads/php/files/tiuik6tqigjhmi5n4kptd3u8g2/ragowe.pdfIn PDF document text
    • https://lifecareproduct.in/ckfinder/userfiles/files/kobutuxorenalipukatos.pdfIn PDF document text
    • https://goooinggroup.com/userfiles/files/20210906_020050.pdfIn PDF document text
    • http://flairpens.ru/uploads/files/funowitunodenulabira.pdfIn PDF document text
    • http://kleinschadenexperte.com/userfiles/file/nedilawuxosavujawori.pdfIn PDF document text
    • https://edinburghpools.com/contents/files/lixirujojesifudukutomuk.pdfIn PDF document text
    • http://elskenecologie.nl/files/renufunabinofemigev.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_off0000d623.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD623 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ee3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE3A 10984 bytes
SHA-256: 8e91236735a6483f980e19bad8f6ce919297a1ef9af5716e89e4e7cde8a2cd56
font_02_sfnt_off00010777.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10777 17932 bytes
SHA-256: 9d2d36553ef07f2f9f32a3f69644ccacd1be672ce2fb0d6ab488ded7c138a72a