Malicious PDF — malware analysis report

Static analysis result for SHA-256 d3e469f84d806947…

MALICIOUS

PDF

70.2 KB Created: 2021-10-03 10:07:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 12a1e46f6c9e79762cf2dd55b87cec0b SHA-1: 804bd0794d58c26816ee02bb41115178bb75ff1a SHA-256: d3e469f84d80694746d8619a40d373a333394d256cdd00770179f71f12e06fde
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised WordPress upload directories or are part of a link farm hosted on disposable domains. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware delivery through these links. No scripts were extracted, and the document body was unreadable, but the link farm structure is a common tactic for distributing malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://krisoc.ru/uplcv?utm_term=writing+styles+in+literature PDF link annotation
    • http://sichera.eu/userfiles/files/18327636267.pdfIn PDF document text
    • http://isdoor.ru/uploads/files/35157478592.pdfIn PDF document text
    • http://www.johnknox.ch/wp-content/plugins/formcraft/file-upload/server/content/files/16133c1d983ac1---66997300465.pdfIn PDF document text
    • http://fuzoku-kyujin.jp/ckfinder/userfiles/files/33528353388.pdfIn PDF document text
    • http://vibrosystem.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1614245e515316---mimekolovetiwulexa.pdfIn PDF document text
    • http://clinivetmadonnadirosa.eu/userfiles/files/1709238313.pdfIn PDF document text
    • http://needychild.org/ckfinder/userfiles/files/temovigewesekari.pdfIn PDF document text
    • https://kuepancong.com/contents/files/25973794831.pdfIn PDF document text
    • http://express-service-auto.fr/ckeditor/ckfinder/userfiles/files/54720208968.pdfIn PDF document text
    • http://ff-engineering.com/userfiles/files/nezifoputu.pdfIn PDF document text
    • https://qeyeoptical.com/ckeditor/ckfinder/userfiles/files/92260830016.pdfIn PDF document text
    • http://studiotecnicoprato.eu/userfiles/files/27167137551.pdfIn PDF document text
    • http://truhlarstvi-strakonice.cz/files/file/dosekafezixoze.pdfIn PDF document text
    • https://www.hmgfinance.com/ckfinder/userfiles/files/kiniregobonopalul.pdfIn PDF document text
    • https://agencement-menuiserie-var.fr/stockages/files/rigawufuvemoberotoxije.pdfIn PDF document text
    • http://cs-web-design.de/ablage/userfiles/files/54712340681.pdfIn PDF document text
    • http://drivescuolaguida.it/userfiles/files/viroxegevufawileb.pdfIn PDF document text
    • http://finalbrand.cz/upload/file/nujilexe.pdfIn PDF document text
    • https://iveducentar.com/uploads/assets/file/gunixutagewisox.pdfIn PDF document text
    • https://spherule.org/wp-content/plugins/super-forms/uploads/php/files/fkc50gkuae1gdauusl25edkvk6/jujewowesoxozudarejuja.pdfIn PDF document text
    • https://abcoegypt.com/userfiles/files/newakiw.pdfIn PDF document text
    • http://artattack-concerts.de/files/file/lerisakutisibak.pdfIn PDF document text
    • https://protradingindia.net/userfiles/file/wirogugizudazizugosiriwef.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_off0000b33b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB33B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cb4d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB4D 15804 bytes
SHA-256: e504536193ecbcf2e3e10c282fd3f8f45c7f86ab39290cd7a1b2b5c964f16e81
font_02_sfnt_off0000f3cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3CD 10372 bytes
SHA-256: 5402b1af50ce17ed27a853de5cecf7b4214d07cfe9d8cb8d2fa6e4d3b3f717fd