Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0ff4939dd657898…

MALICIOUS

PDF

81.7 KB Created: 2021-09-18 20:46:27 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 3141425117b1e2ec0015433761de59ea SHA-1: 9d8641c1ed40f3c48b13adf33770148e73ef0fa0 SHA-256: a0ff4939dd6578982ef353762d834ec55dd2f97d70b4dae5d0f318a2fb87905d
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. The document contains numerous links to compromised WordPress upload directories and other disposable hosting, suggesting it is part of a link farm designed to distribute malware. The presence of a 'download button' heuristic further supports the intent to trick users into downloading a malicious payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9955

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
  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130417d4f6c6---majuweginozokod.pdf
    • http://anhuishangbiao.com/upload_fck/file/2021-9-13/20210913091653229208.pdf
    • http://kwiatmetal.pl/userfiles/file/53651437240.pdf
    • https://cailux.lu/userfiles/files/24270756724.pdf
    • http://limeitec.com/upfiles/editor/files/85084362519.pdf
    • http://nachhilfeschule.havonix.com/ckfinder/userfiles/files/tezexirozufipikopibi.pdf
    • http://www.introspekta.si/ckfinder/ckeditor_uploaded_files/files/23329225177.pdf
    • https://luathoanghuy.com/uploads/files/13892905566.pdf
    • https://www.hungryalex.com/wp-content/plugins/super-forms/uploads/php/files/4421ae906037d1c7b3fd2d1020784aad/81729463392.pdf
    • https://francoisdaulte.com/ckfinder/userfiles/files/gudemikipinigedaten.pdf
    • http://pmrs.ps/userfiles/file/45554614656.pdf
    • https://galaxytraining.examinationonline.com/files/54900854564.pdf
    • https://www.xcelsus.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613f0afbd2bfb---xukebeb.pdf
    • http://studiomarcheluzzo.it/userfiles/files/purav.pdf
    • http://www.anclupnapoli.it/userfiles/file/48605972899.pdf
    • http://koslita.eu/ckfinder/userfiles/files/vagidisejoweb.pdf
    • http://sushiloverca.com/uploads/files/gavamedasuxigorudewer.pdf
    • https://skywaytravelandholidays.com/ckfinder/userfiles/files/mogomemadawufomexapiz.pdf
    • http://mrspk.com/ckfinder/userfiles/files/gisevolebolerubafenopolib.pdf
    • http://ecoevopublisher.com/files/upfiles/file/xedalawara.pdf
    • http://www.nandomoraes.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/161435d7fe0db3---31978973958.pdf
    • http://tajesink.com/Uploadfiles/files/suxebozodemojegikopod.pdf
    • http://cimkezes.hu/uploads/ckfinder/userfiles/files/91540066497.pdf
    • http://agierresrl.it/userfiles/files/dunuguwewajitez.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=talking+tom+run+mod+apk
    • 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_off0000dc7b.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDC7B 16792 bytes
font_01_sfnt_off0000f48d.bin
06b76c11046137e7b5bb7566fd35cf7a38b7e579f36ee1c18255160896afb879
pdf-font-stream PDF embedded font (sfnt) at offset 0xF48D 17540 bytes
font_02_sfnt_off000121c0.bin
94986b3870a67a6e609888c62d52e56c2192302200631a1949768117fea9666a
pdf-font-stream PDF embedded font (sfnt) at offset 0x121C0 10592 bytes