Malicious PDF — malware analysis report

Static analysis result for SHA-256 a0a3c9a94d702f71…

MALICIOUS

PDF

80.1 KB Created: 2021-09-01 11:26:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: fde9ec8e33126190e9db802205b79a51 SHA-1: 1e1564df09846d1f4c1e9e45ba5783645b593e47 SHA-256: a0a3c9a94d702f71a07d001965cce58900694c9afb7267b4d23b3d5b81ea024f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a link farm pointing to multiple compromised WordPress sites, indicating a phishing or redirection attempt. The ML classifier and ClamAV detection strongly suggest malicious intent, likely to lure users to malicious content or exploit vulnerabilities. The presence of external URIs and link farms on compromised CMS uploads supports the phishing and exploitation attack patterns.

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://floorco.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/0f789eaf5d6a3c573a53d429aa814a27/vugulakatasutu.pdf In PDF document text
    • https://www.audifonosdoshoydos.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bf4dabc01e---dupusugatolikogekeretexe.pdfIn PDF document text
    • https://grandplaza.bg/uploads/assets/file/45261628538.pdfIn PDF document text
    • https://asiarsolutions.com/userfiles/file/37482335130.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/cfqa5u3bdm492mgeejau4nf6ei/57282730933.pdfIn PDF document text
    • http://taiwan-tsai.com/upload/files/78670387257.pdfIn PDF document text
    • http://uniondeautoescuelas.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606c7866a97d9---28191612976.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606eed0eceb32---52477592167.pdfIn PDF document text
    • http://dirpub.org/editor/ckfinder/userfiles/files/57231241377.pdfIn PDF document text
    • http://thaoduocvn.com/userfiles/image/file/pozuwuxaj.pdfIn PDF document text
    • http://4x4autok.hu/userfiles/files/lidusuvikokuwa.pdfIn PDF document text
    • http://svx.su/ffile/file/11350172966.pdfIn PDF document text
    • https://nguyenvanhuongloc.vn/app/webroot/files/images/pages/files/fireginawomepisaje.pdfIn PDF document text
    • http://autavrabek.cz/obrazky/file/vulamu.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160fdac0c5be1a---kovujeronazasom.pdfIn PDF document text
    • https://gmonlinestore.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c772d01cee2---midurepizapimozemozu.pdfIn PDF document text
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c4dbcc5709d---xopuludaxerinegeguziramof.pdfIn PDF document text
    • http://hyeminshop.com/DATA/files/dabaredu.pdfIn PDF document text
    • https://comodee.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4bf498804c---12958749928.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/LPIa9PGmDLg/uplcv?utm_term=wavelength+meaning+in+tamilPDF 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_off0000ca84.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA84 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e296.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE296 22472 bytes
SHA-256: 73ce41753021c829397b81068fe11cb61275bd883266dd1fd6513f518d9552f2
font_02_sfnt_off00011ccf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11CCF 10224 bytes
SHA-256: b943d1266a662c5d42765012030b44f86501252218cc8581436e4d173aecd516