Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef348c21ce0d0e79…

MALICIOUS

PDF

80.5 KB Created: 2021-07-14 06:45:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 82e4b8ba331af62f92e906169d648691 SHA-1: ad59f81d7883ba1437503ca0270e773bc5f2520c SHA-256: ef348c21ce0d0e798849d63859da73aeb61640b9495cd07af3921bbbcb4f4389
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload directories or disposable hosting. The ClamAV detection and ML classifier strongly indicate malicious intent, likely phishing or malware delivery. The file's structure and URL patterns suggest it's part of a link farm designed to obscure the ultimate destination and evade detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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://www.laterveer-biesenbeek.nl/ckfinder/userfiles/files/kapototaxidizupubikujor.pdf
    • http://specimport.by/files/files/kabebidunat.pdf
    • https://dezsredstvompx.ru/wp-content/plugins/super-forms/uploads/php/files/efed3d2651e4dd37bf665408de850ed1/derinodikopupilobageleme.pdf
    • http://argra.rs/wp-content/plugins/formcraft/file-upload/server/content/files/16080812718baa---wunasawikabobib.pdf
    • https://aihr-iadh.org/uploads/FCK_files/file/vavenoginazeri.pdf
    • https://rescue.bg/wp-content/plugins/formcraft/file-upload/server/content/files/160baf81cb3ba7---74570215846.pdf
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/ac686766ad15cb8664cc7e05da7ea402/fetosadojegofaxejofoso.pdf
    • https://www.brunosistemi.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ccbd31a2058---gafalugumerominedu.pdf
    • http://churchliferesources.org/wp-content/plugins/formcraft/file-upload/server/content/files/1607b983879cf5---3745667925.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160d08b3a962d8---jebefidomijupa.pdf
    • https://gservicepz.com/wp-content/plugins/super-forms/uploads/php/files/88df4149dc32b5a67454d6b90fa4a212/xevufikejuvivad.pdf
    • http://www.meglobalinc.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609b58aade7c1---gidimozane.pdf
    • https://ahreco.com/uploads/news_file/35333690458.pdf
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/1607761b3cfb69---4482080479.pdf
    • http://hongshengfish.com/uploadfiles/2021052314593352579.pdf
    • http://myexamadvisor.com/fck_uploads/files/83644755488.pdf
    • http://titadoorbinhduong.com/upload/files/88000046827.pdf
    • http://aclamerica.com/customers/CMS-IMAGES/file/kimuv.pdf
    • http://www.festivalmarrakech.info/wp-content/plugins/formcraft/file-upload/server/content/files/160a8ebc5b6126---70419028001.pdf
    • https://moniimpex.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d8ed167a448---milizukox.pdf
    • https://sesconbs.org.br/ckfinder/userfiles/files/76854574256.pdf
    • http://kingspec.su/wp-content/plugins/super-forms/uploads/php/files/eqf8qqasms2ccrbn3rj2pgfcoq/fuxobom.pdf
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c997be2a86---58661455123.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=the+assassin%27s+blade+book+order
    • 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_off0000d706.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD706 16792 bytes
font_01_sfnt_off0000ef18.bin
17a756b6ea79016a5a077fc2b733ab38c784af0156d7a23b1eb2e4057df8db2d
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF18 17200 bytes
font_02_sfnt_off00011b9c.bin
e1715390ec46a18e14f5a2ea0173df38abf587c55ca030038d82e14610310699
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B9C 10476 bytes