Malicious PDF — malware analysis report

Static analysis result for SHA-256 8b4a823a71011f71…

MALICIOUS

PDF

80.7 KB Created: 2021-09-12 09:52:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 4b53dc00b310a5b9ce8e32bbb62a0d7a SHA-1: 587c61b4c861cbb23bab6e171950488afe4483c2 SHA-256: 8b4a823a71011f7109d728a9e138f7b43281dae23e8153508eb8edf5a1614f9a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to deliver second-stage payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • 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://drafthe.ru/uplcv?utm_term=french+league+soccer+table PDF link annotation
    • https://daquin-ferriere.fr/userfiles/file/revimorar.pdfIn PDF document text
    • http://ximangsongthao.com/app/webroot/uploads/files/86076984184.pdfIn PDF document text
    • https://villadorottya.hu/uploads/frontend/files/50730751942.pdfIn PDF document text
    • https://www.ibyservice.com/wp-content/plugins/super-forms/uploads/php/files/86389df7c1c9a75cce145203b08fc0bb/30446592675.pdfIn PDF document text
    • http://nuyewpilot.academy/wp-content/plugins/super-forms/uploads/php/files/f43ac16a213532f2f8f01093af0da737/32848940985.pdfIn PDF document text
    • http://partner-support.net/user_data/userfiles/files/87038085396.pdfIn PDF document text
    • http://hasicimosnov.cz/foto/Image/file/97029422907.pdfIn PDF document text
    • http://lehnerkom.de/images/uploaded/file/muragonofobababiniruxi.pdfIn PDF document text
    • http://azizolace.cz/images/file/sejixelepogusaferipojilem.pdfIn PDF document text
    • http://vector-luczak.pl/new/fck_user_files/file/bavelotufajifupinuxeboli.pdfIn PDF document text
    • http://veraschwemmle.de/fckdata/file/pavanamepedogosi.pdfIn PDF document text
    • https://www.displaysdirectaustralia.com.au/application/third_party/ckfinder/userfiles/files/nekajovenirerufanu.pdfIn PDF document text
    • https://vizzzio.ru/wp-content/plugins/super-forms/uploads/php/files/1d1a50748af71dbb1a4147008a98c10a/fafotukiregelo.pdfIn PDF document text
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/09vm7o7eivt5t6sroc05f3uhf3/634936042.pdfIn PDF document text
    • http://kiemdinhcan.com/Images_upload/files/30738702355.pdfIn PDF document text
    • http://www.elmundodelapiscina.com/ckfinder/userfiles/files/38969411618.pdfIn PDF document text
    • https://jin-ji.com/upload/files/jumedunodapadizejafevet.pdfIn PDF document text
    • http://leguido.net/files/50615038330.pdfIn PDF document text
    • https://internationalmedia.com/userfiles/file/jeloxebir.pdfIn PDF document text
    • https://emenu.hu/editor_up/duzaxoronanoguda.pdfIn PDF document text
    • http://ziepniekkalns.lv/wp-content/plugins/formcraft/file-upload/server/content/files/16139e93b723e5---74561933536.pdfIn PDF document text
    • http://zhizhencn.com/filespath/files/20210905165957.pdfIn PDF document text
    • https://rougezenekar.hu/files/file/98896768485.pdfIn PDF document text
    • https://hoakhanh.vn/uploads/image/files/lujutarajudij.pdfIn PDF document text
    • http://aj-freight.com/ckfinder/userfiles/files/donesiro.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_off0000d501.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD501 18508 bytes
SHA-256: 1e7e38b1c555b21758b0e6a634fc46f2d7be86503de1b80673d6d6c507e2af7d
font_01_sfnt_off0001050a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1050A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011d21.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D21 10636 bytes
SHA-256: 47413536e7c5432e8504b2e3c7bd79f4aaa040e6ec45b964711d6dba4356677e