Malicious PDF — malware analysis report

Static analysis result for SHA-256 a1def7ff5fcf6fe5…

MALICIOUS

PDF

83.5 KB Created: 2021-09-10 22:28:00 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: aba8652fe4eb3339c2f1df880a87bdeb SHA-1: e17cbe32e20f6e5276655f74511a596a18d044e2 SHA-256: a1def7ff5fcf6fe51c08a5f53dc6dba40ebda748f2184dcb341facc4ce61103b
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains embedded JavaScript and numerous external URIs, many of which point to disposable hosting or compromised WordPress uploads, suggesting a link farm designed to redirect users. The presence of JavaScript indicates an attempt to execute code within the PDF viewer, likely to facilitate further malicious actions.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://laborke.ru/uplcv?utm_term=best+pdf+restriction+remover
    • http://milcontabil.com.br/wp-content/plugins/super-forms/uploads/php/files/0fsoc5b30k5flpij7li3o1m6u7/35930602079.pdf
    • http://www.majbrno.cz/uploads/files/nefojawuxitanipuvizitix.pdf
    • https://olivermilk.vn/tctt/sites/aaa/file/xalokesi.pdf
    • http://sk-massimo.com/js/upload/files/duwelupefuzarabuzovu.pdf
    • http://kozelsk-adm.ru/files/uploads/files/57050762052.pdf
    • https://lean-ds.com/upload/editor/file/bavixarebod.pdf
    • http://geriatriccarenewjersey.com/userfiles/files/duxewekurowokivaneb.pdf
    • https://sindhuinvestment.com/ckfinder/userfiles/files/lekejewokuwelaxejubi.pdf
    • http://muaah.ca/userfiles/files/54035666990.pdf
    • http://i-akparat.kz/ckfinder/userfiles/files/71899666276.pdf
    • https://coopinproject.eu/ckfinder/userfiles/files/41663677153.pdf
    • https://mpressivelabels.com.au/application/third_party/ckfinder/userfiles/files/86437949874.pdf
    • http://www.whirlpool-beachcomber.at/wp-content/plugins/formcraft/file-upload/server/content/files/161346a907c57b---kozejevigufo.pdf
    • https://hatinhjobs.com/upload/files/71147711186.pdf
    • http://ydis.kr/userfiles/file/061602167921.pdf
    • http://inventory-acepipe.com/images/uploads/files/borofixutafobelizikoduwum.pdf
    • http://uniondrygoods.com/fckeditor/userfiles/file/jelawunimo.pdf
    • http://geometrabottero.it/userfiles/files/93283556590.pdf
    • http://vip-cond.ru/userfiles/file/79056102723.pdf
    • https://celovechurch.org/wp-content/plugins/super-forms/uploads/php/files/015994b27d98eebe056abfab75dbbd5d/wolakibaguzenuv.pdf
    • http://bkm-market.net/userfiles/file/fanuwolojosoxox.pdf
    • https://e-midas.ro/files/file/boputuxijubojezotose.pdf
    • https://pharmawell.eu/ckfinder/userfiles/files/ruxobezolanejew.pdf
    • https://bharatceramics.in/ckfinder/userfiles/files/tubolenuxubofaxoze.pdf
    • http://hzosm.com/images/upload/File/93660146266.pdf
    • 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_off0000e413.bin
241607e5ba301886efe8f563c915ba560104a5e84f14689a09482f528485931e
pdf-font-stream PDF embedded font (sfnt) at offset 0xE413 10692 bytes
font_01_sfnt_off0000fca2.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCA2 16792 bytes
font_02_sfnt_off000114b4.bin
3fce87bc9b732166ba4e3f552389c6df8d370da0c9e17a797556f047b5c95269
pdf-font-stream PDF embedded font (sfnt) at offset 0x114B4 16768 bytes