Malicious PDF — malware analysis report

Static analysis result for SHA-256 683e068b2cbddd78…

MALICIOUS

PDF

79.1 KB Created: 2021-09-02 02:04:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7f81829189c3f9f2d2b531ec244e84da SHA-1: 12fd4534e66486a84e74a5b8a47b23b1fc5054cb SHA-256: 683e068b2cbddd78866e6c8e1b928c9912f34fd660bcf989234ac08792488f58
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample was identified as malicious by ClamAV and an ML classifier, with high confidence. It functions as a link farm, hosting numerous PDF files on compromised CMS upload directories. These links likely serve as lures for phishing attacks or to distribute further malware. The document body was unreadable, but the heuristics and URLs strongly indicate a malicious intent to redirect users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.chicagoalphas.com/wp-content/plugins/formcraft/file-upload/server/content/files/16097546c61c40---33578424290.pdf
    • http://structurecreative.com/wp-content/plugins/formcraft/file-upload/server/content/files/161131b018d165---moxepupuwakorekawulategij.pdf
    • https://www.db-ynox.fr/ckfinder/userfiles/files/subuzanaxizunodo.pdf
    • http://appletechsolutions.com/userfiles/file/4290672497.pdf
    • http://xn--dlek-5qa.com/admin/UserFiles/file/votozubulelozowonefena.pdf
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/7b18b38238d22a862c2672528169924c/76944085451.pdf
    • https://vegan-eshop.cz/data/file/42511059325.pdf
    • https://geneolock.com/locktactyuma/userfiles/file/39087764841.pdf
    • https://www.hinkler.com.au/application/third_party/ckfinder/userfiles/files/33734907103.pdf
    • http://klenderbio.com/upload/files/7686010545.pdf
    • http://graphicon.hu/wp-content/plugins/formcraft/file-upload/server/content/files/16093b4103489e---dudon.pdf
    • http://www.afamaresme.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b6a7d097b4d---52045047701.pdf
    • http://rc-modeller.se/images/file///56284488849.pdf
    • https://www.blondel-bois.fr/ckfinder/userfiles/files/pumuwitu.pdf
    • http://www.tlo.ntou.edu.tw/ckfinder/userfiles/files/xovepar.pdf
    • https://isabellepieman.com/userfiles/file/bajom.pdf
    • https://shining4u.com/wp-content/plugins/super-forms/uploads/php/files/4a21e7c9e54316fe10d3c705e658be7b/54533583748.pdf
    • https://yuktiedu.com/wp-content/plugins/super-forms/uploads/php/files/c42d5b956f7750109fa2c9063a8530e9/49691320763.pdf
    • http://chenruichem.com/upload/files/munabev.pdf
    • http://fukaofoods.tw/uploads/files/202109020231032994.pdf
    • https://www.sussexweddingservices.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16085cb01e626d---fajozuxasanoz.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=how+many+water+bottles+a+day+are+you+supposed+to+drink
    • 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_off0000cd6a.bin
79cc898f44252f72f433e71721a94e91b1fee367c79f28955aafd2d118050d7e
pdf-font-stream PDF embedded font (sfnt) at offset 0xCD6A 11076 bytes
font_01_sfnt_off0000e700.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE700 16792 bytes
font_02_sfnt_off0000ff12.bin
ec91a598091d1d80b5af88ae8194dd6e7b7f3cfb3829a0a8ada25636f8bc21d9
pdf-font-stream PDF embedded font (sfnt) at offset 0xFF12 17924 bytes