Malicious PDF — malware analysis report

Static analysis result for SHA-256 a9bcbf07c79c0583…

MALICIOUS

PDF

69.7 KB Created: 2021-09-26 12:49:15 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ad94d2f19dc10f9a1541892b333f6a7f SHA-1: e501d6c306d374f6a987a35b31230ba6ef85c38f SHA-256: a9bcbf07c79c05833f69218574f5a0fd4edb70c54587c6b531887d933656d948
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a large number of external links, many pointing to compromised or disposable domains, suggesting a link farm designed to redirect users to malicious sites. The ML classifier strongly indicates maliciousness. While no scripts were directly extracted, the PDF structure and embedded URIs are indicative of a phishing or malware distribution lure, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 5

  • 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://smidgel.ru/uplcv?utm_term=dj+it+mod+apk+download PDF link annotation
    • https://lwim-ouargla.dz/ar/files/77463869683.pdfIn PDF document text
    • https://www.kindspring.org/inc/ckfinder/userfiles/files/sezugunajo.pdfIn PDF document text
    • https://ketdoanbus.com/webroot/img/files/89434470529.pdfIn PDF document text
    • http://protech.com.ng/wp-content/plugins/formcraft/file-upload/server/content/files/16149d76e79819---janepujebube.pdfIn PDF document text
    • https://rosycaffe.com/file/losasikinefutu.pdfIn PDF document text
    • http://joyearland.com/ckfinder/userfiles/files/43057201589.pdfIn PDF document text
    • http://festivaldeliteraturadepereira.com/wp-content/plugins/formcraft/file-upload/server/content/files/161408e81eae7c---47201442667.pdfIn PDF document text
    • http://luatsugiadinhviet.com/upload/ck/files/gifasodovijetilutukesome.pdfIn PDF document text
    • https://pnp-studio.com/fckeditorfiles/file/45680113596.pdfIn PDF document text
    • http://thesecurityguardunion.ca/userfiles/files/mujesimu.pdfIn PDF document text
    • http://veganogle.es/uploads/ckfinder/files/26354783350.pdfIn PDF document text
    • http://divyabodhanam.org/userfiles/file/tafamona.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1614c0ee1c7695---98630375932.pdfIn PDF document text
    • http://ekorepetycje.eu/Upload/file/lokevemofovolijawiku.pdfIn PDF document text
    • http://daotaoyduoc.org/wp-content/plugins/super-forms/uploads/php/files/f764b0bc2bd70ac36201b8a9776c4c27/fajokawaxopulumepavu.pdfIn PDF document text
    • http://beerskiboot.de/img/upload/file/togabotedigoke.pdfIn PDF document text
    • http://burchiellati.com/file_fck/file/bezazedisek.pdfIn PDF document text
    • http://badischer-kunstverein.de/ckfinder/userfiles/files/xesarogolesomojapojagigo.pdfIn PDF document text
    • http://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/finenag.pdfIn PDF document text
    • http://lamorenj.com/userfiles/files/7750709567.pdfIn PDF document text
    • http://xn----dtbhwhggdaoqfh3d.xn--p1ai/media/file/wokulatuvejoxipizajifara.pdfIn PDF document text
    • https://photojet.bg/userfiles/file/58666812362.pdfIn PDF document text
    • https://rimsball.com/ckfinder/userfiles/files/41952940802.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_off0000b1ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB1EA 15580 bytes
SHA-256: 2511d9a7ad10fb070530ec6b08cd58dbfde56dc6760c07e2cb5176abaa08e2ca
font_01_sfnt_off0000d95d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD95D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f174.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF174 10460 bytes
SHA-256: baefbc1e1be12002a72922cd07ffac15f1e9d805e9eb86017fb7075c40fa488c