Malicious PDF — malware analysis report

Static analysis result for SHA-256 c1fd9355c9075f89…

MALICIOUS

PDF

75.4 KB Created: 2021-09-22 19:20:51 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: ed76ec58ce8a75d01fd91594b6e65852 SHA-1: 8972079072cd0e5e80bc5d9ddc2be87c213296b2 SHA-256: c1fd9355c9075f894491304a3511cfe74e979f0bb8259dd93b85260c3a022dde
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. Heuristics reveal it functions as a link farm, with many URLs pointing to compromised CMS uploads or disposable hosting, suggesting a phishing or malware distribution scheme. The presence of multiple external URIs and link farm indicators supports this attack pattern.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://dispecom.com/cms_dispecom/sgi_userfiles/userfiles/files/nixusubutodu.pdf In PDF document text
    • http://www.armstrongre.com/files/files/44176754040.pdfIn PDF document text
    • http://argentum.com/wp-content/plugins/super-forms/uploads/php/files/qsvpoqhu2ojq1caegciq6tgqmt/78160841286.pdfIn PDF document text
    • http://onsijsselstein.nl/userfiles/files/56749279486.pdfIn PDF document text
    • https://nedimgame.com/calisma2/files/uploads/15827244359.pdfIn PDF document text
    • https://bomando.bomsolar.com/uploadfiles/files/gezulubinifinovojobipib.pdfIn PDF document text
    • http://associatedreclaimed.com/userfiles/files/kifelirakarewebeguz.pdfIn PDF document text
    • https://terrebleue.org/userfiles/file/15997245474.pdfIn PDF document text
    • https://theshamrockpublecco.it/file/16191853524.pdfIn PDF document text
    • https://www.capitalroofingct.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613260c3ce03f---pepefajusenunekobak.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149f4fc7e734---317307444.pdfIn PDF document text
    • http://cheliabinsk.realxenon.ru/uploads/files/16576635215.pdfIn PDF document text
    • http://cutyoursupport.com/userfiles/file/bivom.pdfIn PDF document text
    • http://yaan121.com/uploads/files/202109221920418274.pdfIn PDF document text
    • http://koovappadyscb.com/ckfinder/userfiles/files/wedefepupokinepapabiperu.pdfIn PDF document text
    • http://ros.by/ckfinder/userfiles/files/48339018060.pdfIn PDF document text
    • https://szabobuszberles.hu/files/files/tuzilur.pdfIn PDF document text
    • https://mmgrowersg.com/ckfinder/userfiles/files/45065228815.pdfIn PDF document text
    • http://htwy.com/upload/file/69693661418.pdfIn PDF document text
    • http://bdsps.org/slbdavbatala/userfiles/file/12284558916.pdfIn PDF document text
    • https://motoquadro.de/userfiles/file/4652412605.pdfIn PDF document text
    • https://justforjetscatering.com/userfiles/image/files/zuvajama.pdfIn PDF document text
    • http://thuocnam.xyz/images/files/tovovudor.pdfIn PDF document text
    • http://marktoby.com/akram/know_news/admin/userfiles/file/puripumebonuj.pdfIn PDF document text
    • http://oldstat.ww.tj/img/file/12017817545.pdfIn PDF document text
    • http://greenplanetnepal.com/userfiles/file/fupawulokapakaxe.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/zMnd8XtcwSM/uplcv?utm_term=final+account+movie+onlinePDF 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_off0000c40b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC40B 10268 bytes
SHA-256: cfad959bd76ddc1051270b0866ca3577a004c46b42b17113fcd1293a38ba6ee6
font_01_sfnt_off0000db1d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB1D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f32f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF32F 17460 bytes
SHA-256: bd14a256a25a4e1345b612e43d9e3ebc629c0256c02af56d120c813f0ca6e671