Malicious PDF — malware analysis report

Static analysis result for SHA-256 e3658b7a56d26402…

MALICIOUS

PDF

80.2 KB Created: 2021-09-22 13:11:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 0b291baddd35dd9b05fa7196c5ea6381 SHA-1: 09843d87ba105ddf8ebb8defc151e75f7cb191ac SHA-256: e3658b7a56d26402e77ed2c078c5dea7b8e8a241ade5ddde9bc005e91584c68e
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was detected as malicious by ML classifiers and ClamAV, indicating a phishing or trojan threat. It contains numerous embedded URLs, many of which point to domains that appear to be part of a link farm, a common tactic for distributing malicious content or conducting phishing campaigns. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically flags this behavior, suggesting the document's primary purpose is to redirect users to potentially harmful external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9846

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://inwebjor.ru/uplcv?utm_term=arcsin+arccos+arctan+graphs PDF link annotation
    • http://gzky.cn/dubeite/ckfinder/userfiles/files/20210918_115141.pdfIn PDF document text
    • http://mistral-paints.cz/userfiles/files/41363047031.pdfIn PDF document text
    • http://dobre-jaja.com/Upload/file/mobexubafas.pdfIn PDF document text
    • https://wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/jiporeletudokidaxoj.pdfIn PDF document text
    • http://xn--49s538bo8ux8c.net/userfiles/file/vemigesevopatoxugijeliral.pdfIn PDF document text
    • https://gegeny.hu/uploads/file/85886064503.pdfIn PDF document text
    • http://avanti.pl/userfiles/file/jemojezura.pdfIn PDF document text
    • http://profitoolinfo.ru/ckfinder/userfiles/files/62451229304.pdfIn PDF document text
    • http://telek-trans.hu/editor_up/16949947357.pdfIn PDF document text
    • https://cargobull.cz/res/file/jotefisoralatobo.pdfIn PDF document text
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/161405deb4336f---81530341324.pdfIn PDF document text
    • https://hoangphatdanang.xetnghiemadndanang.com/uploads/image/files/79520158179.pdfIn PDF document text
    • https://vongtaytramhuong.vn/upload/files/63586496452.pdfIn PDF document text
    • http://squarcialupirelaxinchianti.com/writable/public/userfiles/file/depexugojum.pdfIn PDF document text
    • http://jingluo.net/uploadfiles/files/wefilepavawigaledoju.pdfIn PDF document text
    • http://yksskj.com/ckfinder/userfiles/files/71230806460.pdfIn PDF document text
    • http://jljemc.com/upload/files/9322189562.pdfIn PDF document text
    • https://amthanhanhsangchinhhang.vn/upload/files/saroziritiwovabotelazis.pdfIn PDF document text
    • https://e-motorcycle.tw/upload/emotorcycle/files/87174670072.pdfIn PDF document text
    • http://fairbank-ia.org/admin/ckfinder/userfiles/files/72726536927.pdfIn PDF document text
    • http://csc0351.com/userfiles/file/20210916172629_2a46uk.pdfIn PDF document text
    • https://cfaegaianascente.pt/portal/userfiles/files/76218425049.pdfIn PDF document text
    • http://prime-standard.com/piceditor/file/nujukibafa.pdfIn PDF document text
    • https://thingstodobahrain.net/ckfinder/userfiles/files/19154442867.pdfIn PDF document text
    • http://enotecagaribaldi.it/userfiles/files/xofanutebelavuxuxugokogim.pdfIn PDF document text
    • http://bridgesonthepark.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135ca73ba33e---63976937963.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_off0000d47f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD47F 18196 bytes
SHA-256: 4c3d45f52647cc75e23a27615d7af4facd1f66e4bf17f8ab64163e76f43afc27
font_01_sfnt_off0001039c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1039C 10456 bytes
SHA-256: 1b24055b8428e8bb3a77a2ecd4c33239dcb8e4f46dbd70b9788f344290a8dd00
font_02_sfnt_off00011b54.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11B54 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1