Malicious PDF — malware analysis report

Static analysis result for SHA-256 6f33c7710b823f08…

MALICIOUS

PDF

74.5 KB Created: 2021-09-27 15:28:25 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: d57af49fbd7614ae8b80ca54aaa7fc76 SHA-1: 16edffdcebad6215d6bbc5f6e2881aae6ba5699f SHA-256: 6f33c7710b823f08324898d5fc410342194ad2653977cf5d30be81a967749f55
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 potentially compromised CMS upload directories or disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely to lure users to phishing or malware distribution sites. The sample's structure as a link farm suggests an attempt to obscure the ultimate destination and leverage potentially compromised infrastructure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613a4fb6c88e9---63087231710.pdf In PDF document text
    • http://chengzechem.com/upload/files/51614558622.pdfIn PDF document text
    • http://formpart.com/upload/ckfinder/files/90943506682.pdfIn PDF document text
    • https://sanidom.pl/img/file/titepipexarinovugojotibu.pdfIn PDF document text
    • https://www.scmsgroup.org/ckfinder/userfiles/files/56525278370.pdfIn PDF document text
    • http://zvezda-rostov.ru/ckfinder/userfiles/files/65247712352.pdfIn PDF document text
    • http://el-master.ru/userfiles/file/sexokamifitotedajer.pdfIn PDF document text
    • http://scea.edu.mn/ckfinder/userfiles/files/mafije.pdfIn PDF document text
    • http://dealershop.es/camarasegovia/userfiles/file/rivekipu.pdfIn PDF document text
    • http://vinag7furniture.com/app/webroot/files/editor_upload/files/8422206297.pdfIn PDF document text
    • http://ophirtonhotel.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16142f02d0b4bf---ditosoxufewutuje.pdfIn PDF document text
    • http://salsainkonstanz.de/media/files/lapubifa.pdfIn PDF document text
    • https://kme.pl/global/app/webroot/uploads/file/16323379379223.pdfIn PDF document text
    • http://maydemtienvn.com/upload/files/62264231125.pdfIn PDF document text
    • http://crystalnymph.by/wp-content/plugins/super-forms/uploads/php/files/78cda946bdce0b9a6936daebb66fc144/jedopimolafajifaku.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/s4uuueune5n2sh72lls5s09uu5/tamotilixi.pdfIn PDF document text
    • http://zeci.nl/im/image/losugixufu.pdfIn PDF document text
    • https://www.mclarenpress.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f7aa5b9f96---givove.pdfIn PDF document text
    • https://borgopitti.it/userfiles/file/4711851744.pdfIn PDF document text
    • https://ssekolkata.com/ckfinder/userfiles/files/11110282308.pdfIn PDF document text
    • https://readxyz.com/wp-content/plugins/super-forms/uploads/php/files/87f83d67d047e677a5d578c6e0719cd8/zedivaxaxofaxek.pdfIn PDF document text
    • http://zaintik.org/files/galeria/files/zefisaruziwigu.pdfIn PDF document text
    • http://www.bongbansaigon.com/uploads/files/negumowidowe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/zMnd8XtcwSM/uplcv?utm_term=black+shark+3+joyui+12PDF link annotation
    • 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_off0000b7e5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB7E5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cffc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCFFC 10828 bytes
SHA-256: 16d0d7c4e4733fe8026077663bfd4bbf0e83c879f0d37123200becbe9ea051e9
font_02_sfnt_off0000e92f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE92F 19652 bytes
SHA-256: 4d6b11447869dc1713e2b9b8cbb5b154b276a9418556a7274c737a1d7b3f4ddf