Malicious PDF — malware analysis report

Static analysis result for SHA-256 36c8df12ca669a81…

MALICIOUS

PDF

85.3 KB Created: 2021-09-19 06:28:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 5308ff34d019ade8945faed06325bc90 SHA-1: 6faaa8f4dab7cbded7e742e12c23c696cf84fc4f SHA-256: 36c8df12ca669a81a44942e46719d480cae2afa45df6a9fd5c9dbd5aa3c2bf18
156 Risk Score

Malware Insights

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

This PDF was flagged by multiple heuristics as malicious, including a ML classifier and ClamAV, indicating it is likely a phishing or malware distribution lure. The PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics suggest the document contains a link farm pointing to potentially compromised or disposable hosting, designed to redirect users to malicious sites. No scripts were extracted, and the document body was unreadable, but the presence of numerous embedded URLs strongly supports a malicious intent.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9974

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://mcap.cz/images/uploadedimages/file/29119255058.pdf
    • https://sailstudy.in/ckfinder/userfiles/files/towozifapavevuralojupike.pdf
    • https://lorenzonimmigrationlaw.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613a02ee2815d---zigetebokijimubusiluvivo.pdf
    • http://tabbanbros.com/admin/fckeditor/editor/filemanager/connectors/upload/file/wewewagulurefadezi.pdf
    • http://teusz.pl/UserFiles/file/9850318790.pdf
    • https://hargagila.com/uploads/image/files/remig.pdf
    • http://combatkuntao.com/ckeditor/ckfinder/userfiles/files/kovojokenit.pdf
    • http://k1a.ru/images/files/file/64435242613.pdf
    • https://tp-pos.com/uploads/image/files/ruxotelosovupisojunoxu.pdf
    • http://bettynblue.com/upload/fck_img/20210919/file/bagivigujidimonobo.pdf
    • http://www.valathors.com/ckfinder/userfiles/files/dazarabizumigikeka.pdf
    • http://mega.kz/media/upload/files/mufefalafotuxebanumo.pdf
    • http://palirna-frydek.cz/uploaded/file/pesidewakadebadelu.pdf
    • https://palet-school.com/files/files/48720622188.pdf
    • https://shian-jin.com/UserFiles/files/xaxazulu.pdf
    • https://egyptsuntours.com/userfiles/files/dudiforeritumezutizu.pdf
    • http://studiodugnani.it/userfiles/files/26665047648.pdf
    • https://rgcsmt.org/ckfinder/userfiles/files/tavegerapuw.pdf
    • https://letstravelforacause.com/miet/assets/files/xuzitisegodegiwog.pdf
    • http://nontaromclinic.com/ckfinder/userfiles/files/pesupuposudejelaraseba.pdf
    • https://www.lindopoint.it/wp-content/plugins/super-forms/uploads/php/files/cc1898f8961233ae1d4147ed55fb01f9/nifawabipifuxupisopod.pdf
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613f5a059f3b0---67177963461.pdf
    • http://hoclaixebinhthuan.com/upload/contentFile/file/petawutezadoxuzupodonisip.pdf
    • http://bowlingkillers.com/imgdb/files/jijarufasikegov.pdf
    • http://sysquare.com/UserFiles/files/69751202380.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1xuhb7AK25c/uplcv?utm_term=soap+android+studio
    • 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_off0000e6ee.bin
fe3a92c2f55092e4a776c31edd7436a5b345d01214a0ecf73d33b2e648ed9aa4
pdf-font-stream PDF embedded font (sfnt) at offset 0xE6EE 18776 bytes
font_01_sfnt_off000117bd.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x117BD 16792 bytes
font_02_sfnt_off00012fd4.bin
d5b646d74e7aa95b0baecdfe3da281acce4517cd964212d18b447c736984003d
pdf-font-stream PDF embedded font (sfnt) at offset 0x12FD4 10380 bytes