Malicious PDF — malware analysis report

Static analysis result for SHA-256 79b8b316fc1f2500…

MALICIOUS

PDF

85.3 KB Created: 2021-09-13 14:55:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 513fa79bc41d180d1aef399809572f22 SHA-1: ccb9ff3bd08d7ec02ec31a77db1c77bfcceb8d9a SHA-256: 79b8b316fc1f2500b6f4514ec00e0c061c7ced21a69f4fd34e716b4997309f89
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 domains identified as link farms on disposable or potentially compromised hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware delivery. The document body is heavily obfuscated and unreadable, providing no direct user-facing content but the structure and heuristics point to a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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 http://tramtronbetong.com/uploads/userfiles/file/80681877716.pdf
    • https://webgirls-studio.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a0d03d02c6---70579290818.pdf
    • https://facades-et-traditions.com/actualites/file/xegad.pdf
    • http://studiotecnicobonoli.com/userfiles/files/xalepinevidakuke.pdf
    • https://happy-playground.gr/uploads/_uploads/files/wifewawolonowedirejeno.pdf
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1613e985e82689---natab.pdf
    • http://www.ondebiz.com/userfiles/file/pebum.pdf
    • http://bilcafe.it/userfiles/file/zozedu.pdf
    • http://benthanhsgfarm.com/images/uploads/files/31547761208.pdf
    • http://le-lemniscus-incandescent.fr/ckeditor/upload/files/57663847590.pdf
    • http://luxe-pools.fr/i/File/tuzozos.pdf
    • https://widepolymers.com/userfiles/file/96707602709.pdf
    • https://www.colegiodesafio.net/home/wp-content/plugins/formcraft/file-upload/server/content/files/16136fe6328a92---77541462980.pdf
    • http://4998horo.gmmwireless.com/contents/files/49666525815.pdf
    • http://consoles-a-gagner.com/fckeditor/userfiles/file/ripujevifironerafatu.pdf
    • http://alpinist.store/sribati/editor/uploadfiles/nugomixenefuxobabaxiwejap.pdf
    • https://euronet.stonavka.cz/webpagebuilder/ckfinder/userfiles/files/3620321702.pdf
    • https://gppacdatabase.net/userfiles/file/bivikeduruvalexi.pdf
    • http://yjbiotech.cn/upload/files/31511842720.pdf
    • https://perfecthospitals.com/ckfinder/userfiles/files/gojimupi.pdf
    • https://www.glasswindowequipment.com/wp-content/plugins/super-forms/uploads/php/files/2d97a6aa774a46a91b899bf062a60091/68384509586.pdf
    • https://delphin-restaurant.com/ckfinder/upload/files/vuxagefagulopelor.pdf
    • https://www.larche-de-jules.fr/ckfinder/userfiles/files/sakawena.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=captain+america+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_off0000e8e0.bin
41733e9615895669e1db0bd0d1a9e216f1dd37da846f5941d69d4adf3a8f3d38
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8E0 17824 bytes
font_01_sfnt_off000117b5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x117B5 16792 bytes
font_02_sfnt_off00012fcc.bin
560bfb10c441d21353b4dcf060d7186221ac74716e54a56d18e928a60fbd49cb
pdf-font-stream PDF embedded font (sfnt) at offset 0x12FCC 10480 bytes