Malicious PDF — malware analysis report

Static analysis result for SHA-256 c823373dd63ebc4f…

MALICIOUS

PDF

69.7 KB Created: 2021-09-28 07:32:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: f33b56032a7cf5176e5a66c7456997ce SHA-1: 88e2cdaf97faa1fa26a49818f5f1eb88371e1d47 SHA-256: c823373dd63ebc4fdb97ab96cd11d4e84574bd148fdae89b11295acf40ebd659
156 Risk Score

Malware Insights

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

The PDF contains a large number of embedded URLs, many of which point to compromised CMS uploads and disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to serve further malicious content. The document body was unreadable, but the heuristic findings clearly point to a link farm designed to lure users to external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/161509bebd6971---41439109735.pdf In PDF document text
    • https://liantoong.com/archive/upload/files/83782409312.pdfIn PDF document text
    • https://foundationkuzmanov.com/files/91680839486.pdfIn PDF document text
    • http://chaputlawoffice.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/50102126229.pdfIn PDF document text
    • http://terezmisszio.eu/files/file/93162415354.pdfIn PDF document text
    • http://jsqnchem.com/upload/files/kevoganezibufezob.pdfIn PDF document text
    • https://laflammerouge.ch/userfiles/files/69962812314.pdfIn PDF document text
    • http://toszegisuli.hu/userfiles/file/patifelunojupomafew.pdfIn PDF document text
    • http://sowaprojekt.pl/files/file/65011182153.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files/rexinilizonenatojasu.pdfIn PDF document text
    • https://telechips.com/ckfinder/userfiles/files/pubaw.pdfIn PDF document text
    • http://tuyothuyluc.vn/webroot/img/files/33316815710.pdfIn PDF document text
    • http://costruzionibulagna.it/userfiles/files/zisonetiz.pdfIn PDF document text
    • https://rpaxis.net/userfiles/file/sobututalunireritugutig.pdfIn PDF document text
    • https://mtmnetwork.net/uploadEditor/files/76431285105.pdfIn PDF document text
    • http://ei-windykacja.pl/upload/file/79769060142.pdfIn PDF document text
    • http://aucontecnologia.com/userfiles/files/pomijidagixibofefogopez.pdfIn PDF document text
    • http://pc580.cn/upload_fck/file/2021-9-21/20210921001114326519.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/1614e6303b9e2b---76964533523.pdfIn PDF document text
    • https://albawadiroad.com/userfiles/files/81551410153.pdfIn PDF document text
    • http://ativn.com/upload/file/vebomos.pdfIn PDF document text
    • https://podiummagazinenews.com/ckfinder/userfiles/files/26215886677.pdfIn PDF document text
    • http://www.ddu-hk.cz/ckfinder/userfiles/files/10293727463.pdfIn PDF document text
    • http://npxbyy.com/wang3_3_10_27/Upload/Upload/file/202195651423910.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/cv9VXjIrmdE/uplcv?utm_term=snes9x+android+apkPDF 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_off0000b24a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB24A 15276 bytes
SHA-256: 214aa7e338c4ff302e1332cf53dc56d939329cd60fe25af50f2ab736e9c1243c
font_01_sfnt_off0000d8e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD8E7 10676 bytes
SHA-256: 744514bdc49eed457884aaf11ced034532ebec3a59fc77e17b51d029f36e39c4
font_02_sfnt_off0000f180.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF180 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1