Malicious PDF — malware analysis report

Static analysis result for SHA-256 4165dfe841f63ac2…

MALICIOUS

PDF

71.7 KB Created: 2021-10-03 13:53:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 5e10d0a1798908c2cf6af0d98cb007e6 SHA-1: 01ee53d25f39aaa4b90584dd9511f932dc79dcf0 SHA-256: 4165dfe841f63ac2b3fcf8b9dcfa760a8070fd2d29b658b28ddd967e57606cdd
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 compromised WordPress installations, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, so the rationale is based on the URL analysis and heuristic firings.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 https://ehblending.com/wp-content/plugins/super-forms/uploads/php/files/61486255e17ad4978b0329f8a998d03d/voravizalut.pdf In PDF document text
    • http://onlinecommerce.bg/uploads/pages/files/goruz.pdfIn PDF document text
    • http://dj-venci.com/uploads/pages/files/36278823667.pdfIn PDF document text
    • http://lavalnerina.com/userfiles/file/dovubasobumumupi.pdfIn PDF document text
    • https://petroblend.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b76d3eb80a---49679333035.pdfIn PDF document text
    • http://gardensyellowcab.com/admin/images/file/4463379828.pdfIn PDF document text
    • https://universal4shipping.net/userfiles/file/vulevivagubonewevu.pdfIn PDF document text
    • http://littlepearlspublishing.in/data/eimages/file/41028792179.pdfIn PDF document text
    • https://ascend.sut.ac.th/ce/2017/src/plugins/ckfinder/userfiles/files/susukut.pdfIn PDF document text
    • http://symbolfoods.com/files/file///36084543232.pdfIn PDF document text
    • http://iranjobex.com/cache/fck_files/file/41552220486.pdfIn PDF document text
    • https://www.partyshuttlebus.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/161455d5d7e719---rirajivozejiniwoda.pdfIn PDF document text
    • http://ajarnveerapong.com/UserFiles/file/32170985458.pdfIn PDF document text
    • https://reazfarah.com/ckfinder/userfiles/files/kozafu.pdfIn PDF document text
    • http://seychelles-resort.com/images/blog/file/54071118151.pdfIn PDF document text
    • https://partroyfuneralhome.com/partroy/assets/file/famajig.pdfIn PDF document text
    • http://oprandi.it/userfiles/files/redenukugabemebuvuwumojos.pdfIn PDF document text
    • https://kibledergisi.net/resimler/files/70167377415.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/e3r7j9sgpc5vodiqh1atf9urh5/38411330961.pdfIn PDF document text
    • http://kaie.org/userfiles/file/20210913185845.pdfIn PDF document text
    • http://martonelektro.hu/files/file/xarowudafafi.pdfIn PDF document text
    • https://ensegun2.com/ckfinder/userfiles/files/80675062446.pdfIn PDF document text
    • http://fu-xin.tw/uploads/files/202109222018172536.pdfIn PDF document text
    • http://ahaadesign-com-tw.sales-frontier.com/ckfinder/userfiles/files/fasopupogatedumuv.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/BvfzZFkJO3s/uplcv?utm_term=10+day+smoothie+cleanse+day+2PDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b457.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB457 17364 bytes
SHA-256: 72ac3ccd73b00215e6a59041be655d6f7d358d2deebbefda9abbd6da644c3d82
font_01_sfnt_off0000e09c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE09C 10848 bytes
SHA-256: 263612c43801bb4326a38904f8c57d01df6b6974bf6f75e5ad07a280275edb22
font_02_sfnt_off0000f98b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF98B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1