Malicious PDF — malware analysis report

Static analysis result for SHA-256 41208c4a3c2cfcc8…

MALICIOUS

PDF

73.0 KB Created: 2021-09-27 12:52:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 0b8d93610910c390b1628d79f14a0dfb SHA-1: 33f7963fd89b0b8ce2446751b72ed84848bb3c31 SHA-256: 41208c4a3c2cfcc8ca97bdebd10b6acba6fe4d53402ee7e164444193670fc650
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The presence of embedded JavaScript and a large number of external URLs, many hosted on compromised or disposable domains, suggests this document is designed to redirect users to malicious sites or download further payloads. The heuristic 'PDF_SEO_DISPOSABLE_LINK_FARM' specifically points to a link farm strategy.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://huntic.ru/uplcv?utm_term=how+to+upgrade+android
    • http://dachastyle.com/userfiles/file/gekigimakogakodavodirasa.pdf
    • http://frederickfollows.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1613a74d24591e---baxakudozazeja.pdf
    • http://laiyi-art.com/userfiles/file/67023235577.pdf
    • http://antwerp-rentals.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613819d9aaa42---38494755117.pdf
    • http://ducthoaudio.com/upload/files/16342850785.pdf
    • http://colonia-hausmeister.de/uploads/files/podulipegivekabafovov.pdf
    • http://yuanyoujie.vip/userfiles/file/7544527326.pdf
    • http://heatherjansch.com/ckfinder/userfiles/files/70342347551.pdf
    • http://thuonghieutoancau.vn/uploads/files/kuvijijipufos.pdf
    • http://www.cpnatacao.pt/backoffice/ckfinder/userfiles/files/85018999613.pdf
    • https://terracell.pt/images/file/vevalizun.pdf
    • https://kvgrup.com.ua/wp-content/plugins/formcraft/file-upload/server/content/files/161458bef5e840---49016861925.pdf
    • http://albino-pitti.com/pub_img/file/46055575756.pdf
    • https://patriciogaete.com/upload/file/bozakefusuxiwafeg.pdf
    • http://the-bom.kr/upfile/files/28127154605.pdf
    • https://hotlinepro.in/admin/userfiles/file/62607443522.pdf
    • http://pcwenhua.com/uploadimg/file/16308195521343040538.pdf
    • https://textosl.com/upload/editor/file/54605491517.pdf
    • http://charugarware.com/DEVELOPMENT/charu_garware/uploaded/userfiles/file/39572848594.pdf
    • http://dnt-mayak.ru/content/File/56888354027.pdf
    • https://singhaniabrothersltd.com/ckeditor/ckfinder/userfiles/files/26913676440.pdf
    • https://www.chauffeur-prive-nice.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1614f2b86bdcfc---61454624980.pdf
    • http://maezawa-jidousha.com/js/upload/files/91438417789.pdf
    • http://osullivanspressurewashing.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f0f9c33878---kowuzubivamenapova.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b8bc.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xB8BC 16792 bytes
font_01_sfnt_off0000d0ce.bin
f1623860ed0290154caa0056d14fb4c6bc6dc7860491c38f882bfef47c511086
pdf-font-stream PDF embedded font (sfnt) at offset 0xD0CE 17900 bytes
font_02_sfnt_off0000ff16.bin
64ed15cd75c6b24f38cf36c3ab964b43d47a3f570cd285778b86afdbbc3e93cf
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF16 10528 bytes