Malicious PDF — malware analysis report

Static analysis result for SHA-256 b4d8f771d1d1d4d0…

MALICIOUS

PDF

88.5 KB Created: 2021-08-12 13:24:01 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c948c8c0949bdadc49a687c351870e1c SHA-1: 1a0132e7db2603521c0ba605b9f9a8c85c4b1098 SHA-256: b4d8f771d1d1d4d023926729725e9e9691e547896094da827cda7df74165df93
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains embedded JavaScript and multiple external links, some pointing to compromised WordPress upload storage, indicating a malicious intent to host or redirect to further malicious content. The 'SE_CALLBACK_LURE' heuristic strongly suggests the document is designed to trick users into calling a fraudulent number, consistent with callback phishing or tech-support scams. The ML classifier and ClamAV detection further support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 8

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://quickvideo.nl/userfiles/file/jekobaduluwikawakunux.pdf In PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/3ee9ca32e87444eb57c1393a42180b55/79966518652.pdfIn PDF document text
    • http://union.travel/ckfinder/userfiles/files/kuzawamejoz.pdfIn PDF document text
    • http://www.justgiveahand.org/wp-content/plugins/formcraft/file-upload/server/content/files/160877d98b9864---68741603595.pdfIn PDF document text
    • https://hanurichurch.org/ckfinder/userfiles/files/22013896995.pdfIn PDF document text
    • https://directprocessors.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607800e5ab288---bipunagugusizafolugamepo.pdfIn PDF document text
    • http://namlongprojects.com/images/uploads/files/84038243156.pdfIn PDF document text
    • https://tlproduct.com/userfiles/file/28711741435.pdfIn PDF document text
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/ccfc70dc27ed18aa9f0bc8222f6630ad/70142361171.pdfIn PDF document text
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/ad13d27a0bae8229be8d9e039cb40544/majavazapepukipopuzomewob.pdfIn PDF document text
    • http://tweddlefoto.com/files_contenidos/upload/files/15906320061.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/44a553bf83c5acb5a67e17b2e461ce14/reniti.pdfIn PDF document text
    • https://mikepromedia.com/wp-content/plugins/super-forms/uploads/php/files/cbrics9icj936781nbnopljrl1/vefojafoliwabapima.pdfIn PDF document text
    • http://elitvorota.ru/f/file/rolororewu.pdfIn PDF document text
    • http://chingyi.tw/userfiles/files/71421010011.pdfIn PDF document text
    • http://titibbs.xyz/js/ckfinder/userfiles/files/5652024125.pdfIn PDF document text
    • https://hmv.ir/wp-content/plugins/formcraft/file-upload/server/content/files/16070e6c47ff03---68429454022.pdfIn PDF document text
    • https://aimhc.com/userfiles/file/67172451085.pdfIn PDF document text
    • http://ciaooo.ru/uploades/userfiles/file/35868210574.pdfIn PDF document text
    • https://songhong.info/userfiles/file/raveku.pdfIn PDF document text
    • http://jtour.vn/userfiles/file/45624970364.pdfIn PDF document text
    • http://olguanaokulu.com/upload/file/temumolekovofeke.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608b99ab0c1e9---45034354186.pdfIn PDF document text
    • http://klubalfa.org/img/userfiles/file/zaxidapesapoluxedorufaru.pdfIn PDF document text
    • https://rmp-traueranzeigen.de/cms/files/18235868372.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/PmAiG5ZyT-k/uplcv?utm_term=how+to+get+a+copy+of+honorable+discharge+papersPDF 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_off0000f440.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF440 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off00010c52.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10C52 17392 bytes
SHA-256: fde719bcc3195ef1f1251fc6d3088c68ec9c5c8308da1df97c7b1381b4b875c2
font_02_sfnt_off00013997.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13997 11228 bytes
SHA-256: 451ac45dcc75369294ec1d8ee380c037264eebe7d72eee3d317563325b497493