Malicious PDF — malware analysis report

Static analysis result for SHA-256 0437a68eb4177f63…

MALICIOUS

PDF

80.5 KB Created: 2021-09-17 13:08:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: fd57be3b8e47b9727841bedb28ff3b23 SHA-1: 99e90f56b9dfc4da220aed502b0688e09967ebba SHA-256: 0437a68eb4177f636080c869c2371e0bd150127e3e05ee1222463b78aaeddd40
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file is a PDF containing numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. No scripts were extracted, but the PDF structure itself is used to host and distribute links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://irlanc.ru/uplcv?utm_term=classical+guitar+music+for+studying PDF link annotation
    • http://bkmarine.net/ckfinder/userfiles/files/1631034925.pdfIn PDF document text
    • https://ebooksweb.net/files/file/biwabexefaguwusuxi.pdfIn PDF document text
    • http://eventclub.pl/userfiles/file/vegibazeboxilag.pdfIn PDF document text
    • http://cs-web-design.de/ablage/userfiles/files/93221729361.pdfIn PDF document text
    • https://www.hadlowsecurityshutters.com/wp-content/plugins/super-forms/uploads/php/files/274ce85f5aafaa0afd517bab50b3dd4d/90002745214.pdfIn PDF document text
    • https://machnhaduong.com/images/uploads/files/32618333746.pdfIn PDF document text
    • http://gernano.eu/gfx/userfiles/files/88093928926.pdfIn PDF document text
    • http://bensonlandscape.com/editorData/file/tegitegididixufikupeki.pdfIn PDF document text
    • http://locthanhroyal.com/upload/files/netogejesojaniz.pdfIn PDF document text
    • http://2446665a.ru/ckfinder/userfiles/files/tubigagadawax.pdfIn PDF document text
    • http://muasamhangmy.com/ckfinder/userfiles/files/wagusolepaweba.pdfIn PDF document text
    • http://cheapneasytrafficschool.com/CheapNEasyTrafficSchool/pa/trainstation/uploads/image/file/76922687743.pdfIn PDF document text
    • http://qianxish.com/ckfind_image/files/sezevatilasamogetupo.pdfIn PDF document text
    • https://www.verpoort-bouw.be/wp-content/plugins/formcraft/file-upload/server/content/files/16137c5ff23e07---zapazafuxi.pdfIn PDF document text
    • https://valeaflorilor.ro/img/uploads/file/80359479679.pdfIn PDF document text
    • http://mindatpeace.us/uploads/files/87812880718.pdfIn PDF document text
    • http://haisushitogo.com/uploads/files/jomefuras.pdfIn PDF document text
    • https://indicaperu.com/userfiles/file/43088460820.pdfIn PDF document text
    • http://laboratoriodiprogettazione-ve.it/userfiles/files/pefabijonu.pdfIn PDF document text
    • https://skatrip.com/basefile/skatripcom/files/88993035272.pdfIn PDF document text
    • https://avis-medical.ma/wp-content/plugins/super-forms/uploads/php/files/f74196d7ad67d82c9bd394dbad17798b/kepekorojuxobaxozexipupa.pdfIn PDF document text
    • https://podereilmontaleo.it/writable/public/userfiles/file/79426939298.pdfIn PDF document text
    • http://showpelec.com/data/file/20210912_065120_649.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_off0000d6a0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD6A0 10932 bytes
SHA-256: e31a86a42b4a93660764df395160333a8027d251fbf9005f2de59258538b1133
font_01_sfnt_off0000efc9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEFC9 17032 bytes
SHA-256: bf39e9baf7a89d61cab549abc2b0954a715b4c8b060e8676859dcdae3932d187
font_02_sfnt_off00011bcc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BCC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1