Malicious PDF — malware analysis report

Static analysis result for SHA-256 c638a99b546eeca9…

MALICIOUS

PDF

82.1 KB Created: 2021-09-18 02:17:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 31ec8981607c1dcd8d95007dcc89ec57 SHA-1: 2506db02c5aae85c2acb23aa572c7f36b1053c81 SHA-256: c638a99b546eeca938cfb97ce527d396527987620dc40348c37c37356153861c
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs pointing to various domains, many of which appear to be compromised or disposable hosting. Heuristics indicate this is a link farm designed to direct users to external content. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware delivery through these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://pixomot.ru/uplcv?utm_term=words+starts+with+ra PDF link annotation
    • http://mebel-moscow.com/content/xuploadimages/file/gewimebav.pdfIn PDF document text
    • http://minisadik-margaritka.ru/admin/ckfinder/userfiles/files/5165747185.pdfIn PDF document text
    • https://vmkstroi.ru/wp-content/plugins/super-forms/uploads/php/files/0a37a3ef9c96256db6901abd4ccde1df/21938930809.pdfIn PDF document text
    • http://www.smwiarus.pl/ckfinder/userfiles/files/50273162106.pdfIn PDF document text
    • https://www.cir.cloud/wp-content/plugins/formcraft/file-upload/server/content/files/16130ce01892a2---sulesodosetu.pdfIn PDF document text
    • https://daulte.com/ckfinder/userfiles/files/xigumuwigosexuxe.pdfIn PDF document text
    • http://metallpress.info/files/majovofakome.pdfIn PDF document text
    • http://dooroc.com/tk/upload/file/20680783298.pdfIn PDF document text
    • http://celyroknaterase.sk/editor_uploads/system/files/30026515019.pdfIn PDF document text
    • http://ctyrkolky-gamax.cz/data/dokumenty/43400525296.pdfIn PDF document text
    • https://unitedfightalliance.com/ckfinder/userfiles/files/pavegodamowaterixesi.pdfIn PDF document text
    • http://refinerlink.com/userfiles/file/58019706092.pdfIn PDF document text
    • https://sts-cct.com/app/webroot/userfiles/files/45210379740.pdfIn PDF document text
    • http://geopraxis.it/userfiles/files/fosililatowuzalaxobofoka.pdfIn PDF document text
    • https://chiataiec.com/userfiles/Proj_Name/files/rifamimuve.pdfIn PDF document text
    • https://www.pferde-fuer-unsere-kinder.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613f5c74a4f0f---dovexejipon.pdfIn PDF document text
    • https://jphotographyllc.com/userfiles/file/2883076800.pdfIn PDF document text
    • http://huemin.com/fckeditor/userfiles/file/15182466418.pdfIn PDF document text
    • http://www.siscbolivia.com/admin/uploaded/fck/file/pimur.pdfIn PDF document text
    • http://gernano.eu/gfx/userfiles/files/84694680630.pdfIn PDF document text
    • http://shopgraeagle.com/ckeditor/uploads/files/rujuvuk.pdfIn PDF document text
    • http://veiligheidssloten.nl/ckfinder/userfiles/files/15099989073.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/zidasopum.pdfIn PDF document text
    • http://vonschickenconcord.com/uploads/files/kaxamewigufo.pdfIn PDF document text
    • http://uniquecharacters.com/upload/files/79947286599.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_off0000db3d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB3D 10144 bytes
SHA-256: 21413dcb6be01e9a9ba89ae9dcc9207f30390e15e77dec07f3b9c57762583268
font_01_sfnt_off0000f20f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF20F 18956 bytes
SHA-256: 6fa39fb22ceebbb30792e3186995086ce2ab1cca44f8cf81708be22c4e3b7fe4
font_02_sfnt_off00012336.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12336 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1