Malicious PDF — malware analysis report

Static analysis result for SHA-256 f384a772e3fe6f3d…

MALICIOUS

PDF

81.7 KB Created: 2021-09-19 19:33:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: e6b644aebb1e4a60a479155848a1103f SHA-1: 64444f80d9f403ed764bb22d8a9add221d5c4c23 SHA-256: f384a772e3fe6f3d4a7d5ec748afd35cc625e4225ceb6029decbc51287e05726
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 numerous unknown PDF files hosted on compromised or disposable domains, as indicated by heuristics like 'PDF_SEO_DISPOSABLE_LINK_FARM' and 'PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM'. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. The document body is unreadable, but the structure and URL analysis are sufficient to infer a malicious link farm attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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 http://ekhoron21.mn/uploads/files/46812872314.pdf In PDF document text
    • http://automozg.by/upload/editor/files/19096096146.pdfIn PDF document text
    • http://soojuspilt.ee/files/file/56527654882.pdfIn PDF document text
    • http://yatros.ro/wp-content/plugins/formcraft/file-upload/server/content/files/1613647984a0e4---86013888214.pdfIn PDF document text
    • https://meesens.be/KrMee/Tekstverwerker/51704999937.pdfIn PDF document text
    • https://kujainspectors.com/candyticket/uploads/page_images/files/64332704409.pdfIn PDF document text
    • http://ccshecea.org/upload/files/23912330474.pdfIn PDF document text
    • https://geniodelweb.com/file/61700032938.pdfIn PDF document text
    • http://gocchame.vn/app/webroot/img/uploads/files/koxiniges.pdfIn PDF document text
    • http://gfk-schwimmbad.de/i/File/mukapapogakilusamudonik.pdfIn PDF document text
    • http://xn--d1achljw0b.xn--p1ai/content/upload/65016737596.pdfIn PDF document text
    • http://zawodydrwali.pl/app/webroot/userfiles/file/68376345997.pdfIn PDF document text
    • https://everywheregenes.com/uploadfile/qu26_qu106_com/files/vukogotojanarelowusar.pdfIn PDF document text
    • http://fotografieindex.nl/images/uploads/raxorukowopepax.pdfIn PDF document text
    • http://www.investing-in-women.com/wp-content/plugins/formcraft/file-upload/server/content/files/16147014e432c0---sugebibux.pdfIn PDF document text
    • http://jtravel.clickis.kr/FileData/ckfinder/files/20210906_D000662F2128F763.pdfIn PDF document text
    • http://mybyblos.com/userfiles/file/41962483562.pdfIn PDF document text
    • http://mesotects.com/wp-content/plugins/formcraft/file-upload/server/content/files/161300e370aada---samapasamutox.pdfIn PDF document text
    • https://agregadoschucuri.sinecsas.com/ckfinder/userfiles/files/mujolonafifegife.pdfIn PDF document text
    • http://hifitness.hu/userfiles/file/wozor.pdfIn PDF document text
    • http://newabel.com/ckfinder/userfiles/files/jikifawox.pdfIn PDF document text
    • https://senesi-sklad.cz/userfiles/file/51190918726.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3vuEKuznOb8/uplcv?utm_term=free+music+player+app+for+androidPDF 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_off0000dcb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCB8 10876 bytes
SHA-256: 1e3d7eb42337feabcaa2654c2717a7ef51f0988479827b193a8fc899b04cc1c3
font_01_sfnt_off0000f5cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5CC 16628 bytes
SHA-256: 7ba2f723695b2f3803dd4e4c3246a849f9011daefe298fd3db2f8c5aa63d6a64
font_02_sfnt_off000120d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x120D4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1