Malicious PDF — malware analysis report

Static analysis result for SHA-256 66243ab88bd05d2c…

MALICIOUS

PDF

72.4 KB Created: 2021-09-13 01:08:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 4db8f5017064ff59f537ca6e2588ec87 SHA-1: 9d7c091a62f33a747dcce43b19416237dc1624a4 SHA-256: 66243ab88bd05d2ca221fdebf4bbe570f3d8b02d19108354a1f44ca69901001c
156 Risk Score

Malware Insights

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

The PDF contains a link farm pointing to compromised WordPress upload storage and other disposable hosting, suggesting an attempt to distribute malicious files. The ML classifier and ClamAV detection strongly indicate malicious intent. The document body is unreadable, but the presence of numerous links to PDF files on various domains points towards a phishing or malware distribution scheme.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

Heuristics 6

  • 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.
  • 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.tocbirsen.org.tr/ckfinder/userfiles/files/vekitumeson.pdf In PDF document text
    • http://www.cuerpomenteyespiritu.es/wp-content/plugins/formcraft/file-upload/server/content/files/16135906abed5f---59370573481.pdfIn PDF document text
    • http://vietnam-intraco.com/webroot/img/files/dozezamixobafuwabexetigaf.pdfIn PDF document text
    • http://americasbestmanassas.com/uploads/files/zikelozowegadav.pdfIn PDF document text
    • http://dogoducthien.com/uploads/files/3719796852.pdfIn PDF document text
    • https://ski-valloire.com/ckfinder/userfiles/files/xinoleranikunak.pdfIn PDF document text
    • https://www.getfitcrew.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f39ba37d51---nalakufefekinufoteritipo.pdfIn PDF document text
    • http://autoachtercamper.nl/userfiles/file/36687128002.pdfIn PDF document text
    • https://hashtag.school/userfiles/file/59256139396.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/16130ec0070293---29268552997.pdfIn PDF document text
    • https://alwaysthesame.pt/site/upload/file/kibuvafurawolumegateva.pdfIn PDF document text
    • http://anm-av.de/uploads/files/28323804362.pdfIn PDF document text
    • http://sarkar.ie/userfiles/file/32069795096.pdfIn PDF document text
    • https://marcuspietrek.de/MARCUS/files/file/walali.pdfIn PDF document text
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b2533b314a---4864462170.pdfIn PDF document text
    • http://anthonyvienna.com/sites/default/files/file/baviromo.pdfIn PDF document text
    • https://iphone-odklep.si/vsebina/89653364349.pdfIn PDF document text
    • http://diamant-x.sk/UserFiles/file/64401328635.pdfIn PDF document text
    • http://neurooperations.com/ckfinder/userfiles/files/53437727253.pdfIn PDF document text
    • http://lamorenj.com/userfiles/file/78890199723.pdfIn PDF document text
    • http://cec-intl.ru/app/webroot/files/file/16766387427.pdfIn PDF document text
    • http://cukiernia-waltar.pl/qcms/userfiles/file/61683413963.pdfIn PDF document text
    • http://tropo-design.com/ckfinder/userfiles/files/kitapijudovirapotilalen.pdfIn PDF document text
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613afacfccf9f---nebimivunuki.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=download+game+akiba%27s+trip+undead+ppsspp+iso+androidPDF 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_off0000b982.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB982 11188 bytes
SHA-256: 8ea3fe152f7813722906cebefd9da77beaa25d597e8b8e15b1933e8bda488ae7
font_01_sfnt_off0000d350.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD350 15788 bytes
SHA-256: b6a68a5170f9150411ba9f3b581bc06341295ea6a3c4dc079fc8ba797566b8aa
font_02_sfnt_off0000fb5c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB5C 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1