Malicious PDF — malware analysis report

Static analysis result for SHA-256 5a5e7342f711bf0b…

MALICIOUS

PDF

83.7 KB Created: 2021-09-08 10:53:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 11ebc143a3733b0705dbc1ef5e9bb95e SHA-1: 3aa0e3a748cf6454814fe7d615b53a4e527c13df SHA-256: 5a5e7342f711bf0b0c6c786d5a60a189a23268c4f217c0001808bbb0d565738b
96 Risk Score

Malware Insights

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

The PDF file contains numerous external URIs and links to compromised CMS upload storage, indicating a link farm designed to redirect users to potentially malicious content. The ML classifier strongly supports the malicious nature of this PDF. No scripts were extracted, and the document body was unreadable, but the heuristic firings clearly point to a web-based lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

Heuristics 5

  • 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://oniceh.ru/uplcv?utm_term=biometrika+tables+for+statisticians+pdf PDF link annotation
    • http://iltorg.ru/upload/file/12448402164.pdfIn PDF document text
    • https://pioneerlift.com/upfiles/editor/files/65678412908.pdfIn PDF document text
    • https://mogilew.ru/userfiles/file/sanuterede.pdfIn PDF document text
    • https://myparrotfood.com/user_files/files/movefofotivi.pdfIn PDF document text
    • http://fairbank-ia.org/admin/ckfinder/userfiles/files/ketojakinagagedopupidoduw.pdfIn PDF document text
    • http://www.sparkprototypes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a2fdeea3a2---56388533352.pdfIn PDF document text
    • https://ilc.ua/wp-content/plugins/super-forms/uploads/php/files/vf5qbt6vo8r2s5qah03cejrin6/62040819395.pdfIn PDF document text
    • https://masterok-kovka.ru/wp-content/plugins/super-forms/uploads/php/files/e61e4f1b7f69fa1094a3a53180016ae7/24782829513.pdfIn PDF document text
    • https://abe-rdc.com/userfiles/file/fisowikufufuni.pdfIn PDF document text
    • http://onlinendttraining.net/files/jeraxerixad.pdfIn PDF document text
    • http://thoitranglani.com/upload/files/vipufipawekafemibefajuse.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16073d3e298402---47903891055.pdfIn PDF document text
    • http://hanifeugur.com/image/files/80365309210.pdfIn PDF document text
    • http://jarosi.hu/files/file/96975130621.pdfIn PDF document text
    • https://ntct-dz.com/ckfinder/userfiles/files/30264616255.pdfIn PDF document text
    • https://keralahappyjourney.com/ckfinder/userfiles/files/jixovibole.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/1607a99f4ba0e3---zitiranivorodumuzisi.pdfIn PDF document text
    • https://eminenceconstruction.ca/viking1/uploads/files/76295580302.pdfIn PDF document text
    • https://terravistahometeam.com/wp-content/plugins/super-forms/uploads/php/files/d4ebeadc63cb0f353b7115184181b9c2/64946352208.pdfIn PDF document text
    • http://dangkyidol.com/wp-content/plugins/super-forms/uploads/php/files/hrrgj84qkdsov5eu846hgf2p60/75668940070.pdfIn PDF document text
    • http://bona-agra.pl/Upload/file/pukotoxajejozofumu.pdfIn PDF document text
    • http://arndt-fahrschule.de/userfiles/file/wixegupagovomo.pdfIn PDF document text
    • http://amon-syotengai.com/userfiles/file/13754209818.pdfIn PDF document text
    • http://hnc2.com/userfiles/file/99854430079.pdfIn PDF document text
    • http://nicenpos.com/userData/board/file/31594268010.pdfIn PDF document text
    • 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_off0000df49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF49 18364 bytes
SHA-256: 31aff7ade921b079d5c7270a5c655d8883435afd8ef790137e128cc97a03b503
font_01_sfnt_off00010f2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10F2F 11064 bytes
SHA-256: 70b0cb26d083d524ee52f16ce82783e3e2ffba80483b1d78e943e40fdc998b8a
font_02_sfnt_off000128bc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x128BC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1