Malicious PDF — malware analysis report

Static analysis result for SHA-256 c81a37ce63faecb6…

MALICIOUS

PDF

84.1 KB Created: 2021-10-08 13:00:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 0e37cc0a9a92a43d31d6e727cb75d1b1 SHA-1: d45725fb32c23bc2612e34bbd540fe413df72899 SHA-256: c81a37ce63faecb632910cbbdc363cba32190593008bf15115a813b65e8f6e87
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics indicate the document functions as a link farm, with multiple embedded URLs pointing to various domains, some of which are hosted on compromised CMS upload storage. The primary purpose appears to be redirecting users to external sites, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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 http://xn--or3bo5mvlb.com/data/editor/file/dozetulewuxopanekid.pdf In PDF document text
    • https://tennis-samara.ru/img/file/5613155217.pdfIn PDF document text
    • https://hung168.tw/UserFiles/files/golizexawavodapijamow.pdfIn PDF document text
    • http://ctm.it/userfiles/file/vonufobujojatebapub.pdfIn PDF document text
    • http://eco-versute.com/app/webroot/ckfinder/userfiles/files/36782671629.pdfIn PDF document text
    • http://tcgardening.com/userfiles/file/2021100711544373499.pdfIn PDF document text
    • https://4wheelchile.cl/admin/uploads/file/86669699192.pdfIn PDF document text
    • https://xn--fiqa735be48e.com/upload/files/tufofopafimasirobiwe.pdfIn PDF document text
    • https://jvlegacyhomerepairsmd.com/nbloom/fckuploads/file/72186418786.pdfIn PDF document text
    • https://cashcruis.ru/wp-content/plugins/super-forms/uploads/php/files/1f4974f620da163d92cac889f688920e/mafawobipenunireseg.pdfIn PDF document text
    • https://cbdc.co/uploads/ckfinder/userfiles/files/vubegowoxa.pdfIn PDF document text
    • https://retentionstudentexperience.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614e741f50239---getevixuva.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a041a8105e---64764739376.pdfIn PDF document text
    • https://contemporaryteas.in/admin/uploads/file/28053467998.pdfIn PDF document text
    • https://atlasautoglass.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615805d49e760---rutefoti.pdfIn PDF document text
    • https://vleek.com/uploads/files/watonemozisutagif.pdfIn PDF document text
    • http://parkergeneralcontractors.net/userfiles/file/sukakinisotot.pdfIn PDF document text
    • http://s-pack.kr/userfiles/file/20211005172158.pdfIn PDF document text
    • https://topclassgreenery.nl/images/file/22483174727.pdfIn PDF document text
    • http://cx-gl.hu/images/files/negev.pdfIn PDF document text
    • https://atx-stroy.ru/wp-content/plugins/super-forms/uploads/php/files/d4c3659d843df6c91a95044813e0a781/kenixat.pdfIn PDF document text
    • https://worldcastlive.com/userfiles/file/85411598980.pdfIn PDF document text
    • http://ttmplus.com/userfiles/files/sivodorudomumaseb.pdfIn PDF document text
    • http://www.altrus.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16147858ded1e0---86225624661.pdfIn PDF document text
    • https://triatlonshop.cz/userfiles/file/93478986053.pdfIn PDF document text
    • https://toscanafantastica.com/userfiles/file/3477782115.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3vuEKuznOb8/uplcv?utm_term=the+plot+of+the+necklace+by+guy+de+maupassantPDF 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_off0000e2db.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2DB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000faed.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFAED 17908 bytes
SHA-256: a1b20fa7044062dfc8624e8048f5568b9d3ea0b1916dbdb48e3d7b5e27955923
font_02_sfnt_off0001285c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1285C 11284 bytes
SHA-256: 9a136e156bac34a11942f2370b1dc80fc2f06940999b98a6cbd5519be289de87