Malicious PDF — malware analysis report

Static analysis result for SHA-256 fb4157816a8babd2…

MALICIOUS

PDF

80.0 KB Created: 2021-09-02 19:34:59 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: 7f889676885e5b8e1339e6c7cfd74a24 SHA-1: 983550eda1abf908f45ffff31fa17c0664bb06ad SHA-256: fb4157816a8babd29c22bee196668ab03a2468fa895a0f94cd3b47950c4bad64
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file was identified as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous URLs pointing to compromised WordPress sites, suggesting a phishing or malware distribution scheme. The PDF structure and embedded links are consistent with techniques used to lure users into visiting malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://smidgel.ru/uplcv?utm_term=reham+khan+book+pdf+in+urdu+translation PDF link annotation
    • https://www.areatransfers.com/wp-content/plugins/formcraft/file-upload/server/content/files/161046f56b7241---27395749986.pdfIn PDF document text
    • https://x-software.cz/data/file/67750590857.pdfIn PDF document text
    • https://webmodels.studio/wp-content/plugins/formcraft/file-upload/server/content/files/160a9864c37507---ramuxifemudanoruditure.pdfIn PDF document text
    • https://www.hinogas.com/wp-content/plugins/super-forms/uploads/php/files/60tu6aqjqikmet0628qlcufl7r/goxavokileb.pdfIn PDF document text
    • https://adikketiga.com/contents//files/29035316206.pdfIn PDF document text
    • https://imagebeaute.fr/userfiles/file/4247114935.pdfIn PDF document text
    • http://tiszaladany.hu/upload/file/4703305602.pdfIn PDF document text
    • http://belovosushi.ru/files/94141157315.pdfIn PDF document text
    • https://psychotherapie-dr-albrecht.de/wp-content/plugins/formcraft/file-upload/server/content/files/1608065e64db0e---66314100170.pdfIn PDF document text
    • https://discoverapartmentsforrent.com/wp-content/plugins/super-forms/uploads/php/files/96b3b42b880d1e50a36bca6a20e2b553/33153476468.pdfIn PDF document text
    • http://diclenakliyat.com/userfiles/file/72492646320.pdfIn PDF document text
    • https://billionbosses.com/ckfinder/userfiles/files/47165123841.pdfIn PDF document text
    • https://stagerightstaging.com/wp-content/plugins/super-forms/uploads/php/files/90396aabd1a1847de43870271284cf9c/gukopegatuselakedelogojav.pdfIn PDF document text
    • https://limpiezasinasel.com/userfiles/files/69278667943.pdfIn PDF document text
    • https://www.quatainvestimentos.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607591f9efaf3---zoworefa.pdfIn PDF document text
    • https://wamsconference.com/wp-content/plugins/super-forms/uploads/php/files/a18154642f6777875b3ac76055d0d7b5/govepogosefanida.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609e6c43c3786---53597584.pdfIn PDF document text
    • http://tolltisztitas.eu/userfiles/files/4279530386.pdfIn PDF document text
    • https://dewalt-naradi.cz/media/upload/editor/file/38065831444.pdfIn PDF document text
    • https://noukos.gr/wp-content/plugins/formcraft/file-upload/server/content/files/160b838b35166e---21464041934.pdfIn PDF document text
    • http://alexhofford.com/temp/files/file/vedibot.pdfIn PDF document text
    • https://deshpanday.com/ckfinder/userfiles/files/kimekutusagoz.pdfIn PDF document text
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/20n2najr481edlcfihs642voeq/tazekadanekowafexotijowu.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_off0000ce15.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCE15 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000e627.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE627 19428 bytes
SHA-256: 6c918a2c42d7e7c4f644b7c502cb8e35cfa0c2d6c7c3e7cda050adc77ee0e124
font_02_sfnt_off00011858.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11858 11140 bytes
SHA-256: d84ec60d4133cd5a4a7c1688be547490954211c0b877d7ed3df9e81e4b1c0ad0