Malicious PDF — malware analysis report

Static analysis result for SHA-256 b763f4c11515c6d5…

MALICIOUS

PDF

103.7 KB Created: 2021-08-16 00:56:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9393edad0b271efaf659d6ad963f9e1e SHA-1: a9021ca782502d195803b7a0f308a29952d34741 SHA-256: b763f4c11515c6d5747d69a9993ebb7d0c852d4f33b167df4ce1410776b64acf
164 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many pointing to compromised WordPress sites hosting other PDFs. This suggests a link farm designed to redirect users to malicious content, likely for phishing or malware distribution. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9984

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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://acornschoolcharleston.org/wp-content/plugins/super-forms/uploads/php/files/ae1c1ed585b95c8916900f68b0f32433/takom.pdf
    • https://ohligschlaeger-berger.de/wp-content/plugins/formcraft/file-upload/server/content/files/16110177240ec1---47161123797.pdf
    • https://www.nordatec.com/wp-content/plugins/super-forms/uploads/php/files/9ro7l9hjoo170r70sssudnqjvg/29721367690.pdf
    • http://www.bridalchapel.com/wp-content/plugins/formcraft/file-upload/server/content/files/160f3961ea4d16---misinilafap.pdf
    • http://barcelonahotel.vn/UpLoadFile/file/vubejuw.pdf
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/16096d68bb67ae---73769205533.pdf
    • https://nikosdimos.gr/userfiles/file/61814628114.pdf
    • http://meyanko.com/userfiles/file///78724769009.pdf
    • http://medica-eg.com/userfiles/file/wifunibodupilorakewabono.pdf
    • http://hoadon-dientu.net/images/files/filiwerofusebodexivo.pdf
    • https://longhoang.vn/upload/files/80178209327.pdf
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607180f2ce255---ditim.pdf
    • http://kibbkw.com/uploads/file/doxawigiru.pdf
    • http://erkerlaender.de/wp-content/plugins/formcraft/file-upload/server/content/files/16082442e20614---fovebefukaw.pdf
    • https://drproperty.in/userfiles/file/29409024247.pdf
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/16071a43848869---kaxetixufi.pdf
    • https://purpleleafestatebuyers.com/wp-content/plugins/formcraft/file-upload/server/content/files/160743e8d7120f---47074300145.pdf
    • http://eurogeographyjournal.eu/admin/fckfiles/file/34468487775.pdf
    • http://ilovechardonnayhills.com/userimages/88687464266.pdf
    • https://jamiatulbanat.in/wp-content/plugins/formcraft/file-upload/server/content/files/16081890ecda32---kunuxetafomulelaw.pdf
    • http://stylist.in.ua/wp-content/plugins/formcraft/file-upload/server/content/files/160ae3bc755a5e---dexubajud.pdf
    • http://phayaotechno.com/UserFiles/File/silidow.pdf
    • http://gildiamasterov.ru/userfiles/file/bumapobija.pdf
    • http://decom.pro/admin/ckfinder/userfiles/files/pasopija.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/6naE_Nh8_CY/uplcv?utm_term=holt+mathematics+worksheets+with+answers+6th+grade
    • 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_off00012f42.bin
aa0dce3f5cf21c069f299f56ed65f487b27b06beabb0a632f90312be816620f5
pdf-font-stream PDF embedded font (sfnt) at offset 0x12F42 11156 bytes
font_01_sfnt_off000148f9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x148F9 16792 bytes
font_02_sfnt_off0001610b.bin
b8fe08b1fbd9bcbef3ddb0a60b8222537fd106f1311628fbb8a52a1d943c0636
pdf-font-stream PDF embedded font (sfnt) at offset 0x1610B 17344 bytes