Malicious PDF — malware analysis report

Static analysis result for SHA-256 7931cb35143f1862…

MALICIOUS

PDF

83.0 KB Created: 2021-09-04 10:35:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: ded8ffa378865472c9161e16265a3642 SHA-1: 5d2befd0aa81aa185a733edfb509a6f3c99caf78 SHA-256: 7931cb35143f18624f497dbbbacf9051961191d15407f2ff59e8342a55478ba5
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm and employs social engineering tactics, instructing the user to press Win+R or paste a command, which is characteristic of ClickFix attacks. While no scripts were directly extracted, the embedded URLs suggest an attempt to redirect the user to malicious content or downloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

Heuristics 7

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://kommunikator.nu/demo/userfiles/file///4027614178.pdf In PDF document text
    • http://compow.net/ckfinder/userfiles/files/novilaladob.pdfIn PDF document text
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160839dd574df3---85504258494.pdfIn PDF document text
    • https://agrotehholding.ru/wp-content/plugins/super-forms/uploads/php/files/335058f96b0989255188e37d6d2ee54c/xisunamosewuwu.pdfIn PDF document text
    • http://ventilyatsia-v-sochi.ru/ckfinder/userfiles/files/firadaxizu.pdfIn PDF document text
    • http://www.firengo.com/userfiles/files/vofododit.pdfIn PDF document text
    • https://arerp.kr/data/file///15429402406.pdfIn PDF document text
    • https://weinquartier.at/wp-content/plugins/super-forms/uploads/php/files/ae61391b7f6a9024309b1893e4df2d3e/xujizivu.pdfIn PDF document text
    • http://bienbao.org/uploads/files/65832960056.pdfIn PDF document text
    • http://ilsogno-bomboniere.com/userfiles/files/nedoxesanenov.pdfIn PDF document text
    • http://copy-office.it/userfiles/file/76111653676.pdfIn PDF document text
    • http://famcareconnect.org/wp-content/plugins/formcraft/file-upload/server/content/files/16070378551387---tixezesafofozisaletin.pdfIn PDF document text
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/c08d683203bab2f0c7ee96bec235b628/52747064703.pdfIn PDF document text
    • http://hayatteknoloji.com/webimage/file/gafamalotuniteg.pdfIn PDF document text
    • http://hengtaixin.com/HangShun/ckfinder/userfiles/files/bovov.pdfIn PDF document text
    • http://arohitourandtravels.com/userfiles/file/34563529042.pdfIn PDF document text
    • http://101balkon.ru/upload/files/jogilavumikaju.pdfIn PDF document text
    • https://euroroma-bg.org/files/file/fisiz.pdfIn PDF document text
    • https://tocgia247.com/wp-content/plugins/super-forms/uploads/php/files/egpqfpt41tuak6lchk8k9ck0sd/15403203535.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/39894633199.pdfIn PDF document text
    • http://wonikqnc.com/upload/editor/file/1624799967.pdfIn PDF document text
    • http://dbexpertise.fr/catalogue_dynamique/file/32281349647.pdfIn PDF document text
    • https://kantankacreative.com/wp-content/plugins/super-forms/uploads/php/files/f74cfa826879bc4db0b7b002f5f78609/momorunisopilexi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=how+to+make+adobe+your+default+pdf+reader+windows+10PDF 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_off0000d8ea.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8EA 19448 bytes
SHA-256: ce3a08f1d6dafa0b3c574e36c63f348b0435d70e6bc8bf6fa2d335b504540c69
font_01_sfnt_off00010bc0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10BC0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000123d7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123D7 11356 bytes
SHA-256: 4b2493271a102260cdfbc1f74f9289d63e4f0f7c91610c686d83a2332af05467