Malicious PDF — malware analysis report

Static analysis result for SHA-256 e8801a1557f0a220…

MALICIOUS

PDF

73.9 KB Created: 2021-09-19 04:04:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: a0a735f2525f0e2a3ffb351f6f63c85b SHA-1: 465d570f1279d7cd7ecd0c750c19da433c81fef3 SHA-256: e8801a1557f0a22094ba515ac52fba53bc39222287e47cbb32c928d3ce410b92
156 Risk Score

Malware Insights

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

The file is identified as malicious by ClamAV and an ML classifier, with heuristics indicating it functions as a link farm. Multiple URLs are present, some pointing to compromised CMS upload directories, suggesting an attempt to host or redirect to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://huntic.ru/uplcv?utm_term=toefl+cd+download PDF link annotation
    • http://3colorjazz.com/fckeditor/userfiles/image/49301308944.pdfIn PDF document text
    • http://skolicka.eu/foto/images/file/vijoz.pdfIn PDF document text
    • https://zevkotodoseme.com/upload/ckfinder/files/sifugiwukumavufalif.pdfIn PDF document text
    • https://fietenhaardenenkachels.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1614072974ab92---xewulil.pdfIn PDF document text
    • http://jinwoosmc.com/userfiles/file/73944458808.pdfIn PDF document text
    • https://xn--atpta-nfb.lv/images/userfiles/files/28087838513.pdfIn PDF document text
    • https://peusch.lu/userfiles/files/1820151965.pdfIn PDF document text
    • http://papienbanana.com/user_file/file/sujufikolulukixirovisewi.pdfIn PDF document text
    • https://sydneystudytour.com/accounting/userfiles/file/35633692057.pdfIn PDF document text
    • http://www.kinoimaging.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16141ffa23ba20---dutotepe.pdfIn PDF document text
    • http://scissortailfarms.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613e890c977f5---nakugowovesaweritawo.pdfIn PDF document text
    • https://phoenixturkey.com/upload/ckfinder/files/96685624047.pdfIn PDF document text
    • https://iskoruma.com/upload/ckfinder/files/kojomipasamegudipopumug.pdfIn PDF document text
    • https://lakecountyoralsurgery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614254995ab4d---lotudikubeguwo.pdfIn PDF document text
    • http://deleeuwputten.nl/site/data/ws/files/leterusugunoteke.pdfIn PDF document text
    • https://ncsccalgary.com/userfiles/files/96594581760.pdfIn PDF document text
    • https://cupanghitam.com/contents/files/11821230661.pdfIn PDF document text
    • http://www.jindatunnel.com/up_files/file/94227066693.pdfIn PDF document text
    • http://u15.ch/ckfinder/userfiles/files/jopakesidabisiratotejib.pdfIn PDF document text
    • https://nolimitscenter.be/peausitive/images/FCKeditor/file/12215197267.pdfIn PDF document text
    • http://www.americaninvest.net/upls/files/19740137055.pdfIn PDF document text
    • http://sooam.com/files/fckeditor/file/232584629613f208df327e.pdfIn PDF document text
    • http://vettercycles.ch/userfiles/files/vinigotefi.pdfIn PDF document text
    • http://limpiasol.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614064830835e---83283163598.pdfIn PDF document text
    • 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_off0000bcc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBCC6 10060 bytes
SHA-256: 79f9df1c38fb2442fb48795264d25caef1179999d528cc64cfb38d15c152a9e3
font_01_sfnt_off0000d353.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD353 17860 bytes
SHA-256: 87d67079d702df44f81ffc677a6f004a901ba1a7dd24e9ab470227c5f5886352
font_02_sfnt_off0001028b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1028B 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1