Malicious PDF — malware analysis report

Static analysis result for SHA-256 a3edb31eae20055e…

MALICIOUS

PDF

80.3 KB Created: 2021-09-06 08:54:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: ff06b585ac9b04c867339ae44ce625cb SHA-1: 735b552005ddd23a4b56ffaf19d1c7e710cce381 SHA-256: a3edb31eae20055ee01c3fc4c9eaeae1c1e5323d02abd9fc9463943c85148c63
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware distribution through these links. No scripts were extracted, and the document body was unreadable, so the attack pattern is inferred from the URL structure and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9949

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 http://bjoybrands.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606e8552daeab---rumibufa.pdf
    • https://www.3dreamchurch.com/wp-content/plugins/super-forms/uploads/php/files/cc61d6e2c9bb78d764d4107bbd02094f/danutomajovarirot.pdf
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/4436fae88083ee767fb47fcd8bceaa2b/sutolijul.pdf
    • http://davidhammerstein.org/ckfinder/userfiles/files/bofif.pdf
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/80d29184934ae7f63d4f3bf5048ed2d6/85436434086.pdf
    • https://www.mercedesbenzofaustinservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c78fb711f6b---foxotasedogufato.pdf
    • https://nicemexico.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609ee3ef6bc34---89249151750.pdf
    • https://www.urban-quartz.co.uk/wp-content/plugins/super-forms/uploads/php/files/196e7df60cb6ac54f53dfe102e50983d/nugekafegupara.pdf
    • http://tnslib.net/userfiles/files/butulo.pdf
    • http://dwallacelaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/sadapatativovezak.pdf
    • https://yellowstonewildlife.com/47372937766.pdf
    • https://www.chesapeake-lighting.com/wp-content/plugins/super-forms/uploads/php/files/274aaf03ce7300b0ca9dfa4c12342153/notetudeberasejisoxige.pdf
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/16081008cb5f6c---19098405354.pdf
    • https://www.swx.global/wp-content/plugins/super-forms/uploads/php/files/695b3617315744ba662d1965fe5ddca2/bopowazunutimofexaletosi.pdf
    • https://dgaspcsm.ro/ckfinder/userfiles/files/4810702620.pdf
    • https://zemiigori.com/uploads/file/buxavefe.pdf
    • http://thuexe7cho.vn/upload/files/89693375895.pdf
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/160c2d71723b4c---tejabesuroguwe.pdf
    • http://www.sunarozlem.com.tr/wp-content/plugins/super-forms/uploads/php/files/fhim8gnjkc39aakc4q7ob23ro2/lejidirinop.pdf
    • https://eyetracking.pl/userfiles/file/pizuxagemixukineritevugi.pdf
    • https://arzhosting.com/calisma2/files/uploads/xutuwapisopumokuwupiro.pdf
    • http://xn--80aaffebba2apgigwiiececnggk9e4k.xn--p1ai/pict/file/7820531521.pdf
    • https://miamivanservice.net/wp-content/plugins/formcraft/file-upload/server/content/files/1609dfff8b5df6---61690313385.pdf
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160ac371fc4ec1---85629671524.pdf
    • http://myucmas.com/userfiles/file/tuperibabeburedebar.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=drawing+speed+time+graph+worksheet
    • 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_off0000d321.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD321 16792 bytes
font_01_sfnt_off0000eb33.bin
b800d2b593bdcea465d72bcdbc8910881ac8bb4736234881fec7cba06ae7d3e8
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB33 18136 bytes
font_02_sfnt_off00011a90.bin
cb4deec1ed87aa2e7cde7b3689543b2c1c0c397be89fa2907f6973e29fcde59d
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A90 10972 bytes