Malicious PDF — malware analysis report

Static analysis result for SHA-256 81b08c0adaf61b8e…

MALICIOUS

PDF

77.0 KB Created: 2021-09-03 17:23:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c8c100b64271addf237fa7e38a4f8c2b SHA-1: be577b5cdc8f7e10001980d39fad7f378bbc5a4b SHA-256: 81b08c0adaf61b8e2c21e5874c9306b328940b1f8d22b4f10dc9cf7ffe75f2cf
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF document was flagged as malicious by ClamAV and an ML classifier. The file embeds a large number of external links characteristic of an SEO link farm, many hosted on compromised CMS upload directories. Specific URLs and indicators for this sample are listed in the indicators section.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9989

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://teenmag.cz/userfiles/file/40630249097.pdf In PDF document text
    • https://www.thecandystoresudbury.com/wp-content/plugins/super-forms/uploads/php/files/27l6ieqak0lst83nsojl9carcr/65125606560.pdfIn PDF document text
    • http://keyflounge.nl/userfiles/file/9403527867.pdfIn PDF document text
    • https://www.vigo.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/160c9ef0bb9664---fenorijofad.pdfIn PDF document text
    • http://thermcom.cz/userfiles/file/55510291904.pdfIn PDF document text
    • https://www.enterpriselighting.com/wp-content/plugins/super-forms/uploads/php/files/4c4ca02b4038f5b1a750e3553ba7c35a/mewufalimiludiluni.pdfIn PDF document text
    • http://beta-rc.com/upload/files/28873719559.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607f641627f96---51596430714.pdfIn PDF document text
    • http://premiumcsp.com/uploads/files/muxisirekevilegun.pdfIn PDF document text
    • https://na-nule.ru/wp-content/plugins/super-forms/uploads/php/files/fb38fa8b6tv4t2f7n60oe4cac7/32470109303.pdfIn PDF document text
    • http://www.tif.cn/wp-content/plugins/super-forms/uploads/php/files/g45ga6uufehdqhvn5i0t6bsrdg/81249656092.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/e22c132de89cb295b3be2ace0739ed08/52707778013.pdfIn PDF document text
    • http://csc0516.com/userfiles/file/20210727073547_ehnv38.pdfIn PDF document text
    • http://ophtalmic-overnight.fr/wp-content/plugins/formcraft/file-upload/server/content/files/160a7dcfb74720---vofekerowipixitedetenewa.pdfIn PDF document text
    • http://oceanstatevolleyball.org/clients/879495/File/powulirizomogujomare.pdfIn PDF document text
    • https://thietkevuphong.com/uploads/image/files/bepegizeride.pdfIn PDF document text
    • http://informerfitness.com/wp-content/plugins/super-forms/uploads/php/files/6f45d9adae4df4a7688e23c9600ce0bf/kobexuxokirupikapezifosa.pdfIn PDF document text
    • http://www.nationaalgolfcongres.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160c5f9039d152---82167297704.pdfIn PDF document text
    • https://plewmal-d.com/Uploads/files/53497366794.pdfIn PDF document text
    • https://alice-immo.com/userfiles/file/81201761122.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=kyocera+cadence+flip+phone+user+manualPDF 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_off0000c765.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC765 10992 bytes
SHA-256: 8918a04dd929e1e1884f79bf0f27d55309e25eaeca9df13579945241e781a5b1
font_01_sfnt_off0000e0a6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE0A6 17812 bytes
SHA-256: 193e43ec7d444f7ab33f713d94589eb740c7cf8b027e3c8510f21d7da1a3a9ba
font_02_sfnt_off00010e4f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E4F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1