Malicious PDF — malware analysis report

Static analysis result for SHA-256 c87fb81d3edf334c…

MALICIOUS

PDF

88.0 KB Created: 2021-08-05 15:24:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 19f9d220c33543d6998b58991ee7166a SHA-1: 8c2d6605419ac06507f1f5cb610fd7a313561ff1 SHA-256: c87fb81d3edf334caa930e269cd42db0e55ceb27dbbc54691f28aa77caf1a22f
156 Risk Score

Malware Insights

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

The PDF contains numerous links pointing to websites that appear to be compromised CMS uploads, suggesting a link farm designed to distribute malicious content or phish users. The ClamAV detection and ML classifier strongly indicate malicious intent. No scripts were extracted from this sample, but the presence of multiple external URIs and compromised host links is highly suspicious.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9957

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.energetisch-therapeut-estie.nl/wp-content/plugins/formcraft/file-upload/server/content/files/161066d22effe7---xazinetur.pdf In PDF document text
    • http://pc75.net/upfiles/file/1623951956.pdfIn PDF document text
    • http://conhantaoankhanh.com/webroot/img/files/13270611706.pdfIn PDF document text
    • http://jullien38.com/ressource/site-image/files/bebinevegokonifixinabopo.pdfIn PDF document text
    • https://laxmigrouppune.com/wp-content/plugins/super-forms/uploads/php/files/ceee1da658c773ffe39fd466b79480b3/rozivokulejuv.pdfIn PDF document text
    • https://www.beewellrx.com/wp-content/plugins/super-forms/uploads/php/files/tmp/77851745859.pdfIn PDF document text
    • https://www.grandiosa.is/wp-content/plugins/super-forms/uploads/php/files/u5saa0qjou36rt1jh8susf6jd7/4221122925.pdfIn PDF document text
    • https://snabavto.com/wp-content/plugins/formcraft/file-upload/server/content/files/160757440947a8---72648761506.pdfIn PDF document text
    • https://mattweidnerlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609a1efd00b7f---10887835547.pdfIn PDF document text
    • http://xn--49s538bo8ux8c.net/userfiles/file/rifatujamimagudigo.pdfIn PDF document text
    • https://lcd96.ru/wp-content/plugins/super-forms/uploads/php/files/47fa1af2bffe7f293238e00912e5ae55/karovepaveguzo.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/951ae3f3899f4c0de7ce5916cb5adc37/59158948741.pdfIn PDF document text
    • http://www.idenet.net/wp-content/plugins/formcraft/file-upload/server/content/files/160f83417094c4---59456369135.pdfIn PDF document text
    • http://accomplishtheimpossible.com/userfiles_ati/file/kuminowurasedanuxevuz.pdfIn PDF document text
    • https://aulacvn.com/upload/fck/file/90373792551.pdfIn PDF document text
    • http://chicagohalo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd292d22a0f---21977070381.pdfIn PDF document text
    • http://www.sunarmisir.com.tr/wp-content/plugins/super-forms/uploads/php/files/nn194lkujl6rht72rdm22a7n81/20196557042.pdfIn PDF document text
    • https://encoregallery.us/wp-content/plugins/super-forms/uploads/php/files/46b4338204a34fbd1a73aadfa5f6172c/68506745241.pdfIn PDF document text
    • http://beastyenergy.com/userfiles/file/87936547933.pdfIn PDF document text
    • https://www.prestigeautobody.com.au/wp-content/plugins/super-forms/uploads/php/files/d49397c984d0820eb4ec6e98c2f2b482/bubasuke.pdfIn PDF document text
    • http://ventilatoryzlin.cz/images/file/86525052985.pdfIn PDF document text
    • http://artospace.com/pics/file/80315067984.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/7tclbfnmv7crhvof9lhrfj4n00/65016326959.pdfIn PDF document text
    • https://badoza.net/userfiles/file/gofit.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c909ee85fae---75463914335.pdfIn PDF document text
    • http://say-international.eu/userfiles/file/99143118647.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=thoracic+outlet+syndrome+surgery+scarsPDF 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_off0000f4de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF4DE 16620 bytes
SHA-256: 7d2d51c3cd5e8f19d99a53aed8bc9cfb3ab1c2e4b50a157e6f95cd0c00d456a2
font_01_sfnt_off00012018.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12018 10992 bytes
SHA-256: e363c5a09cc19dd3d334c76507223a2f00095af15ceacff05cb08b2d5201a0aa
font_02_sfnt_off00013942.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13942 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1