Malicious PDF — malware analysis report

Static analysis result for SHA-256 5dbd9f97c6e10b11…

MALICIOUS

PDF

82.4 KB Created: 2021-06-30 01:44:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: f8f04682e654d62fe1ea7c0e7b25454c SHA-1: 9ccf41bb1a88294e500615bfc2c20f4c4b3b1789 SHA-256: 5dbd9f97c6e10b11fa5caabf877c93a00f5dfad3ae515f78d5ba1f06e96d1ff9
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. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and disposable domains. These links are likely intended to lure users into downloading further malicious content or visiting phishing pages. The PDF structure itself does not contain readable content, but the embedded URLs and heuristic firings strongly indicate a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/8ca5c3f34ced731a0207bbd32ae3e213/ruvof.pdf In PDF document text
    • http://copelandreunionla.com/clients/6/66/66f6f3de7053633686652f51c4c00696/File/kuzamev.pdfIn PDF document text
    • http://saens-jpn.com/ckfinder/userfiles/files/72790473559.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/659300d801e80e67ba29c6444f9ea68f/33900979698.pdfIn PDF document text
    • http://mfplus.ba/wp-content/plugins/formcraft/file-upload/server/content/files/1606fb1da5a4b6---33856718235.pdfIn PDF document text
    • https://leavingcare3plus.ch/userfiles/files/kobowev.pdfIn PDF document text
    • http://muszempilla.com/files/file/57773115259.pdfIn PDF document text
    • https://szamitogep-szerviz-javitas.hu/ckfinder/userfiles/files/pepunuravi.pdfIn PDF document text
    • https://pluckywize.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a3941853271---87894842477.pdfIn PDF document text
    • http://reszke.pl/fckeditor/editor/filemanager/connectors/php/file/69489124903.pdfIn PDF document text
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/16085c4dc96f9c---wajijefawutanuwefav.pdfIn PDF document text
    • https://reifenscho.de/wp-content/plugins/formcraft/file-upload/server/content/files/16098b5528ee9b---suwapog.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/19381852086.pdfIn PDF document text
    • http://ttlengenharia.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160a8a286680b5---56341011341.pdfIn PDF document text
    • http://brilspa.ro/userfiles/file///pezosupogadelotuxewefag.pdfIn PDF document text
    • https://vipbeachhouse.com/uploads/editor/file/gugazanekigexeteputud.pdfIn PDF document text
    • https://www.karenlovelee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c6541635198---futaronek.pdfIn PDF document text
    • http://www.sunarpazarlama.com/wp-content/plugins/super-forms/uploads/php/files/vaqte6i7dh5usfhqtukd10ud24/20722324207.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=how+to+see+an+invite+on+minecraftPDF 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_off0000decd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDECD 10596 bytes
SHA-256: 3a433cd9923c25415e0be8d9a4d9cf6c7528875e38a983e142b46f6152cf011a
font_01_sfnt_off0000f70a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF70A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010f1c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F1C 17376 bytes
SHA-256: 100079a562c057432f3cb36d0e1c7e7c34a20b68a1051f8b1f0d847f0dcb49fd