Malicious PDF — malware analysis report

Static analysis result for SHA-256 0bf81c6a52e2d8fd…

MALICIOUS

PDF

75.6 KB Created: 2021-09-19 00:23:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e141537c3cd32801d04dd8c2e72a5e4d SHA-1: 05ddf7b479262dd2153818187db7a9e567fb0b1b SHA-256: 0bf81c6a52e2d8fdec5f27b08595a07064ccbc182bbc42944cf3231a32a9bae4
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The PDF structure and embedded URLs are consistent with phishing or malware distribution campaigns.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9953

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://inwebjor.ru/uplcv?utm_term=vector+2+mod
    • https://cherrychile.cl/cherry/uploads/contenido/files/zaweruxiduvu.pdf
    • http://ouhkpthaa.org/userfiles/sopagefaremod.pdf
    • http://sochi-polyana.com/ckfinder/userfiles/files/tegezofelagixerarenivav.pdf
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/16140a5d66be06---86974065655.pdf
    • https://cungcapthitdetuoi.com/app/webroot/files/images/pages/files/pigunukoxazuwanofofid.pdf
    • http://cck-brno.cz/ckfinder/userfiles/files/lorurekapumadubixuxezawe.pdf
    • https://duvanco.be/docs/files/zijibofenazoxixesojelufu.pdf
    • https://coolinterier.sk/upload/files/26323698088.pdf
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/806b6fa55ba787a76d0cfec5a5198de7/23167235440.pdf
    • http://foire-fromages-et-vins.com/wp-content/plugins/formcraft/file-upload/server/content/files/16138bfcf3dc6c---wubojezosekat.pdf
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612ee01f45016---nirupiwepupevojofagaki.pdf
    • http://bndweb.nl/upload/files/99176780623.pdf
    • http://women-for-marriage.com/ckfinder/userfiles/files/kigoxijujuxerorunologotu.pdf
    • http://cleangroupbd.com/ck/upload/files/37681745077.pdf
    • http://thetsaban3watnuea.com/UserFiles/file/34095092234.pdf
    • https://inlandautorepairmurrietaca.com/wp-content/plugins/super-forms/uploads/php/files/219be24ff5f43ef73606574bc67650dc/novepavexigi.pdf
    • http://misterholidaysanprisco.it/userfiles/files/rufetorisoladu.pdf
    • http://icmasistemas.com/userfiles/files/daguvepidamumedubepapi.pdf
    • http://gabinetpro.gabinetpro.pl/kosmetyczka/krakow/files/53677619468.pdf
    • http://akekaluck.com/ckfinder/userfiles/files/dafiliporokig.pdf
    • http://www.skupp.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16130e7cd8bc07---kunilavapironudesu.pdf
    • http://smartdeal.pl/files/upload/files/98428579630.pdf
    • https://sibservis.com/ckfinder/userfiles/files/60964256443.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_off0000c85c.bin
85430300794e5e8d3ac754ae93f6b7532e6c8f610af4d8ebb0ae8df9aba0c80a
pdf-font-stream PDF embedded font (sfnt) at offset 0xC85C 16508 bytes
font_01_sfnt_off0000f2bb.bin
7c5ffc82eebff7dc16898c6af7e8b0e83342399765d8f94ba8a41734fb76ea65
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2BB 10048 bytes
font_02_sfnt_off0001092c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x1092C 16792 bytes