Malicious PDF — malware analysis report

Static analysis result for SHA-256 0841b8ca75ac7d1a…

MALICIOUS

PDF

85.6 KB Created: 2021-06-27 19:54:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: dbbfc15150d536e2416ef24ea8548175 SHA-1: e255b2e1e58253f7411851e3cd371515f20c4732 SHA-256: 0841b8ca75ac7d1a2785605a3f60a5d558b4b2a16149bc5193a55ef7d34404cb
156 Risk Score

Malware Insights

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

The sample is a PDF that contains numerous links to external resources, many of which point to compromised WordPress sites hosting other PDF files. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of link farms on disposable hosting suggests an attempt to obscure the true destination or purpose, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://regalcabs.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a2ec69d66b3---wotesenutokawiretudutemo.pdf
    • http://lovesushiscv.com/uploads/files/66815439336.pdf
    • http://www.orarestauratorisaf.it/wp-content/plugins/formcraft/file-upload/server/content/files/16070a7ee54670---vuzimewuragawimuf.pdf
    • https://robotics-institute.com/wp-content/plugins/super-forms/uploads/php/files/oh3leefubiar92j9l53smtpedr/99887113659.pdf
    • http://ecohost.ru/pics/images/file/62739306737.pdf
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160a1fbc42b9f9---13656364908.pdf
    • http://freemansphotography.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b2e4cda8873---xuwisaxafanafevadakega.pdf
    • http://novaserv.com/wp-content/plugins/formcraft/file-upload/server/content/files/160779434b361e---61588730718.pdf
    • http://www.anieliasfx.com/uploads/textareas/file/60220020269.pdf
    • https://careersourceokaloosawalton.com/files/public/18539578124.pdf
    • http://plastikacz.cz/soubory/files/pesezone.pdf
    • http://robwalker.net/fckupload/file/30317298629.pdf
    • https://www.jahnigterbraak.nl/wp-content/plugins/formcraft/file-upload/server/content/files/16097daabf32a2---dejugavewidufirapajibo.pdf
    • http://reiki-roots.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160a7a605dbbd8---9640282657.pdf
    • https://joefairless.com/wp-content/plugins/super-forms/uploads/php/files/dd232e3ea40487ca7f6e4568211fe75a/xedalopopetefamadokebov.pdf
    • https://thealloywheelcentre.co.uk/wp-content/plugins/super-forms/uploads/php/files/a1d35bfb1fa1490051037b9cc4f169c8/gaxakinibemaviduj.pdf
    • https://frontiersneurophotonics.org/wp-content/plugins/formcraft/file-upload/server/content/files/1/1607b93da4aaf6---3437140449.pdf
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/1c93773f5ee46fad14d45ade67c460a4/podiravetufipufidefe.pdf
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/160c4a037e1ef6---72384952706.pdf
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607069b860ea2---94761896465.pdf
    • http://novichiha.ru/pic/file/fiwazufasuwuxamo.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=periodic+table+virtual+lab+answers
    • 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_off0000e9a4.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE9A4 16792 bytes
font_01_sfnt_off000101bb.bin
ef232ffaaa9b4347fc71f17db30fff503938dbe183f1220db52e74f7e2eb7b26
pdf-font-stream PDF embedded font (sfnt) at offset 0x101BB 10756 bytes
font_02_sfnt_off00011aa1.bin
37dc4c7a083e5c85ce7a40402028f8a3afd11304320ebb8317564cb1254e3030
pdf-font-stream PDF embedded font (sfnt) at offset 0x11AA1 17228 bytes