Malicious PDF — malware analysis report

Static analysis result for SHA-256 c9f81b17e7d2b2e0…

MALICIOUS

PDF

85.4 KB Created: 2021-06-27 21:53:33 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: b29994109dd2f0103e56d3ab92818aa8 SHA-1: 92144a5660f0e716732ca3167408c3545adef00e SHA-256: c9f81b17e7d2b2e099e902173e347e21438e7c29c98ca30044738b02efd3918b
196 Risk Score

Malware Insights

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

The sample was detected as a malicious PDF by ClamAV and an ML classifier, exhibiting characteristics of a ClickFix social engineering attack. It contains numerous links to compromised CMS upload storage and disposable hosting, suggesting it's part of a link farm designed to redirect users to malicious content. The PDF's structure and embedded links indicate an attempt to lure users into downloading further malicious files, likely exploiting a vulnerability or leading to a phishing page.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • 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.
  • 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://juniorsmagazine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608c6cef4d03e---36186541103.pdf
    • http://btc-ltd.com/upload/file/bukij.pdf
    • http://decamiones.com/userfiles/file/mefupunozo.pdf
    • https://area34.info/wp-content/plugins/super-forms/uploads/php/files/f88am9rdt4t0hspk5rm0prva33/madaguponi.pdf
    • http://geology.ie/wp-content/plugins/formcraft/file-upload/server/content/files/160d0056778e65---3796743872.pdf
    • https://www.perfumista.co.uk/wp-content/plugins/super-forms/uploads/php/files/36d9258342f293ec9e04ac149f898bfc/79971049876.pdf
    • http://www.next-conseil.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1609426e971223---vobikonedexut.pdf
    • http://goldnumber.info/userfiles/file/mawepiwonidejemo.pdf
    • http://www.oknookna.pl/wp-content/plugins/formcraft/file-upload/server/content/files/1608567d1bc1c4---fuxiruwas.pdf
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/c30d6b1f5bd19c21446705e03bf31c3d/99240238659.pdf
    • http://yuha.be/_files/file/17832582024.pdf
    • https://www.hdontheroadnapoli.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607b56e41e516---72992273762.pdf
    • http://itaindustrial.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160908f7214370---kuforarusapujixuzutudezi.pdf
    • http://maihome.hu/admin1/file/jidilavojoterelimatido.pdf
    • https://centrosteadycam.it/wp-content/plugins/super-forms/uploads/php/files/15fe89ea8abdde80d8a603022a7cae6c/vawanijixuz.pdf
    • http://capitolmetrophysicaltherapy.com/userfiles/file/50628799074.pdf
    • https://www.scanworld.se/wp-content/plugins/formcraft/file-upload/server/content/files/160a866f6a91fe---budakevodugim.pdf
    • https://dungcuruamui.com/wp-content/plugins/super-forms/uploads/php/files/bu1lv1c5uvth88ndo47miubmob/70347989503.pdf
    • http://mid-europe-ex.com/images/blog//file/zofowuzabuju.pdf
    • http://www.photobreak.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1608833da62a56---xotojatisivepazax.pdf
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/tmf766mr1fisqosee3mftlpnu9/64753559102.pdf
    • http://terapie-psi.ro/wp-content/plugins/formcraft/file-upload/server/content/files/16099ae7074838---81941530036.pdf
    • http://www.catalogodecineargentino.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b163b09b860---pijavezigalomos.pdf
    • http://fixmyhelicopter.com/project-new/christianbook/upload_images/file/55243787320.pdf
    • https://advicezone.org.uk/wp-content/plugins/super-forms/uploads/php/files/d03rd8kdmlokjg46a3bnotphiv/62753943126.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/Om9ozkHLxGw/uplcv?utm_term=discord+how+to+screenshare+with+audio
    • 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_off0000dec8.bin
a1cebdfa201f1e97af02ffa183d776d4fe738b6fd1cfe99d41987b6be11539a2
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEC8 22108 bytes
font_01_sfnt_off00011599.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11599 16792 bytes
font_02_sfnt_off00012db0.bin
75978b7b81184b5e6fb4545e9982c7494b35b294cdce062b00dc4f6b2c196037
pdf-font-stream PDF embedded font (sfnt) at offset 0x12DB0 10608 bytes