Malicious PDF — malware analysis report

Static analysis result for SHA-256 281de8c601b9b785…

MALICIOUS

PDF

70.7 KB Created: 2021-09-27 16:33:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 640383c4a1a00ab3a636e06d08116bc9 SHA-1: f3ef161ace78451f37d0664f095c8cf93e2e0660 SHA-256: 281de8c601b9b785a5ea2fd3045b3016a4c6eea7c4b3a9517f19234420793d9f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which are part of link farms hosted on potentially compromised or disposable domains. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. While no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with malicious document lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://coretry.ru/uplcv?utm_term=rfid+card+emulator+android
    • http://zjleiou.com/images/upload/File/86270085853.pdf
    • http://kp-technik.cz/ckfinder/userfiles/files/39479767980.pdf
    • http://longchimvac.net/app/webroot/uploads/files/50137827746.pdf
    • https://greenvalleykerala.com/ckfinder/userfiles/files/mavefozazizeriduziwuzat.pdf
    • https://mannerfeltdesignteam.se/ckfinder/userfiles/files/badololigubuvemom.pdf
    • https://ingatlansos.hu/images/userfiles/file/nuluwalegasarunusularusev.pdf
    • http://asiavent.com/UserFiles/file///tigiputofebutipokejuvoxu.pdf
    • http://polyalpan.hu/_user/file/1495264628.pdf
    • https://arizonapoolcontractor.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f8506790bf---63674285396.pdf
    • https://www.costaverde.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613558779c6aa---najaw.pdf
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/3e55e1e2fea1ab59c73ed251352953a3/4381642207.pdf
    • http://issaproject.com/app/views/panel/ckfinder/userfiles/files/gixisijatipojuvofebikura.pdf
    • http://almawred-sy.com/files/adminfiles/files/31815980564.pdf
    • https://svltv.in/userfiles/files/bejakolinojizem.pdf
    • http://rocincorporated.com/domain.com/images/dynamic_pages/file/496147225.pdf
    • http://www.scmphotography.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1614cc991d24b5---wevajupaneko.pdf
    • http://elmbbq.com/uploads/files/wosikobebupom.pdf
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/161351c6cdb0cb---81942270986.pdf
    • https://derfo.info/resimler/files/88846989916.pdf
    • http://circolosilverblufitnessclub.eu/userfiles/files/3324168257.pdf
    • http://wo-kop.pl/userfiles/file/82143037224.pdf
    • https://intrastorg.com/userfiles/file/19781592469.pdf
    • http://planao.com/ckfinder/userfiles/files/58596364611.pdf
    • http://isagenixmakessense.com/ckfinder/userfiles/files/wetupulabenijo.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_off0000b147.bin
0939481ee015defe532cad4c8ecf46d93c115177fc4eaddece64e2371c0cd0aa
pdf-font-stream PDF embedded font (sfnt) at offset 0xB147 10616 bytes
font_01_sfnt_off0000c983.bin
6a65cf2a11ea4d456fd238c2c0c7f4a36b3163e71c9bdedd7cf026adc9e4a0d1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC983 17004 bytes
font_02_sfnt_off0000f51e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xF51E 16792 bytes