Malicious PDF — malware analysis report

Static analysis result for SHA-256 c2cb88b4b4e12953…

MALICIOUS

PDF

76.2 KB Created: 2021-09-14 11:30:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 5e1bc4b58115932001adf764b7e8812f SHA-1: 3e29876d73851c560e6098304f0c0597f628ff7a SHA-256: c2cb88b4b4e129538f0668b51d4ccbecc3a096032315b2ae4fd29cacd7ade57e
164 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF contains embedded JavaScript, which is often used to redirect users to malicious websites. Several heuristics indicate the PDF is part of a link farm hosted on compromised or disposable domains, suggesting a phishing or malware distribution campaign. The ClamAV detection and ML classifier strongly indicate malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9911

Heuristics 7

  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://cokhivietuc.webthoidai.com/img-vietuc/files/xebirimemerobugomijafit.pdf In PDF document text
    • http://battlegrouponline.com/app/webroot/js/ckfinder/userfiles/files/79659692629.pdfIn PDF document text
    • https://toyotaautobody.com/ckfinder/userfiles/files/47323694862.pdfIn PDF document text
    • http://kebirbeton.com/userfiles/file/zesozogo.pdfIn PDF document text
    • https://www.poolsrus.com.au/application/third_party/ckfinder/userfiles/files/93685608138.pdfIn PDF document text
    • http://artmetinc.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f80112519d---39916723418.pdfIn PDF document text
    • http://www.armstrongre.com/files/files/ritulimom.pdfIn PDF document text
    • https://hotelangela.hu/userfiles/file/7277830964.pdfIn PDF document text
    • http://geometrabottero.it/userfiles/files/64089126536.pdfIn PDF document text
    • https://www.shopveriamici.com/wp-content/plugins/super-forms/uploads/php/files/p17bdg8jcdv143qed1ocd7epb8/widodotibajupap.pdfIn PDF document text
    • https://triatlonshop.cz/userfiles/file/38686845486.pdfIn PDF document text
    • https://ytdrive.com/CKEdit/upload/files/58527355483.pdfIn PDF document text
    • http://intechsol.kz/wp-content/plugins/formcraft/file-upload/server/content/files/16130eb6e6ff8c---fojiregituzamuwofaxisoneg.pdfIn PDF document text
    • https://cs-nippon-cp.com/mailmagazine/upload/files/razozaka.pdfIn PDF document text
    • http://nbnjl.com/userfiles/files/78706148052.pdfIn PDF document text
    • https://luxesystem.site/js/ckfinder/userfiles/files/67205646076.pdfIn PDF document text
    • https://marblo.marblobaths.ph/app/webroot/img/files/72935461760.pdfIn PDF document text
    • http://miyagi.chi-kara.net/Upload/files/35284921065.pdfIn PDF document text
    • http://xnucleus.com/members/member_images/files/83828917021.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/16136f0da40f7f---24527199724.pdfIn PDF document text
    • https://oriental-kitchens.com/userfiles/files/babinuvovaliza.pdfIn PDF document text
    • https://insp.biz/img/file/30716848532.pdfIn PDF document text
    • http://we2meeting.com/ckfinder/userfiles/publics/files/sedalitagimenofidopujogi.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=spoof+user+statistics+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://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_off0000c900.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC900 10588 bytes
SHA-256: 15f97e11381cffd4c43373d45273f1cd2beee32e86e9341ab7130b51beeb4cc1
font_01_sfnt_off0000e163.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE163 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f975.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF975 17680 bytes
SHA-256: 48ae42f3841f4b9d50433a09d5ef988963c9c57335d7cccfb76c1dfa8c8cfa95