Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8f81cd6da7d2da1…

MALICIOUS

PDF

87.7 KB Created: 2021-08-19 16:52:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: b0752cb74092dd7897ce2be20ad54976 SHA-1: 98dc4b177462450ea30c0cd9147f9858fb4ad9f0 SHA-256: a8f81cd6da7d2da1e2e41eaa9f69b74e5e4d64279bad7bfccd3785f514ee2613
204 Risk Score

Malware Insights

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

This PDF document was flagged by multiple heuristics, including a high-confidence ML classifier and ClamAV, indicating malicious intent. The 'SE_CLICKFIX' heuristic suggests a social engineering attack designed to trick users into running arbitrary commands, likely to download and execute a second-stage payload. Embedded JavaScript streams and numerous links to compromised websites further support this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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
  • ClickFix social engineering attack high SE_CLICKFIX
    Document instructs the user to press Win+R or paste a command into a terminal — consistent with ClickFix attacks that bypass macro restrictions by tricking users into running malicious commands directly
  • 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.
  • 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 https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160cb90280b0de---48187531627.pdf In PDF document text
    • https://perfecthospitals.org/ckfinder/userfiles/files/wixubaforudujonup.pdfIn PDF document text
    • http://collegium-connect.nl/ckupload/files/topupabapa.pdfIn PDF document text
    • https://precisionautoandac.com/wp-content/plugins/super-forms/uploads/php/files/bc2ce8949549bf888970e3b67e5ec906/83831730249.pdfIn PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/76099753158.pdfIn PDF document text
    • https://www.vbclighting.com/wp-content/plugins/super-forms/uploads/php/files/8e7bc4de2af24a8fec85a08ee8188288/jokujakiveniderog.pdfIn PDF document text
    • https://socialacademy.gr/wp-content/plugins/super-forms/uploads/php/files/c30f67f523bd4dc2006ca4975900cea5/38434813693.pdfIn PDF document text
    • https://rcvizovice.cz/ckfinder/userfiles/files/70135882635.pdfIn PDF document text
    • http://www.romanschatztruhe.de/img/files/xikujipuvisa.pdfIn PDF document text
    • https://talenthunt.biz/userfiles/file/kasejatezonofazudejojifi.pdfIn PDF document text
    • http://lideparts.com/userfiles/file/1629154352.pdfIn PDF document text
    • https://mission4recruitment.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c50aae3727d---megeli.pdfIn PDF document text
    • http://fabriquetextil.com/js/new/fckeditor/userfiles/file/vewimexu.pdfIn PDF document text
    • https://sensiblemachines.com/ckfinder/core/connector/php/files/tazafizatijubukemujujali.pdfIn PDF document text
    • http://kopdesign.nl/userfiles/file/48695878571.pdfIn PDF document text
    • https://esteticarcare.com/wp-content/plugins/super-forms/uploads/php/files/edb259376aba3ef8982245bacb2af40d/wewetomaxonajen.pdfIn PDF document text
    • https://naseeha.org/wp-content/plugins/super-forms/uploads/php/files/7f21ec2e176a89eb6bfc622b032beb11/28507507650.pdfIn PDF document text
    • http://bapassamarinda.id/assets/ckfinder/core/connector/php/uploads/files/bawimukejetivasudikamu.pdfIn PDF document text
    • https://loan-financial.com/wp-content/plugins/super-forms/uploads/php/files/5ca51f91210522029cc917ede0b7ef68/10220443431.pdfIn PDF document text
    • http://vngo-cc.vn/cooker/public/files/61406673012.pdfIn PDF document text
    • https://samarpanbharat.org/trila/userfiles/file/merogonixaxokojawolaperad.pdfIn PDF document text
    • http://etasystem.net/userfiles/files/vezuwowugupapemifok.pdfIn PDF document text
    • https://glosunspa.com/wp-content/plugins/formcraft/file-upload/server/content/files/160984c4346161---vabeme.pdfIn PDF document text
    • https://www.grecosalesinternational.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080bedb2245a---negikat.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=auto+keyboard+presser+for+roblox+macPDF 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_off0000e71c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE71C 11116 bytes
SHA-256: 4eda4bf3bb5cf146923d863ccb30756f484a4ea7282beaeee33e1bd00ad15294
font_01_sfnt_off000100fb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100FB 21468 bytes
SHA-256: ac984fb64c6cd39b9c4c2cf2bf78ff42e56a714e4828cb4c439b713a6c9b9943
font_02_sfnt_off000137b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x137B1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

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