Malicious PDF — malware analysis report

Static analysis result for SHA-256 e53e33a18ed67e98…

MALICIOUS

PDF

83.2 KB Created: 2021-09-20 02:43:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e79c3f0157925abea96561abec49c32b SHA-1: 9fbd5f666f8e6286097e2768428d4ff9f1384147 SHA-256: e53e33a18ed67e98e900109600408a006e63d79cd0e12a740b43c2c1d3111a7f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The file is a PDF that functions as a link farm, containing numerous URLs pointing to external resources. Several heuristics indicate that these links are hosted on compromised CMS uploads or disposable domains, suggesting a phishing or malware distribution scheme. The ML classifier and ClamAV detection strongly support its malicious nature, likely as a lure to exploit clients.

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://022-web.cn/uploadfile/file/20210902043648195.pdf
    • https://brawlcall.jordanadams.com/ckfinder/userfiles/files/80794889273.pdf
    • http://gmkms.net/upfile_editor/2021/files/38366755772.pdf
    • https://www.truck-transport.com/ckfinder/userfiles/files/tezoreg.pdf
    • https://safe-international.com/userfiles/file/gowusitedabovagalavazatap.pdf
    • http://crm333.com/documentos/file/35218244041.pdf
    • https://www.dentaltaxpros.com/wp-content/plugins/super-forms/uploads/php/files/01ab14968993e4324901eb45fb821b4b/tijapilitipevusonekad.pdf
    • https://christianbelieversmatrimony.com/web/christiansbelieversmatrimony/photos/ckeditor/files/gozoti.pdf
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/6b2ecqq9p3i7fq6cii3j3ihfhr/63444259469.pdf
    • http://abpjseah.news-read.com/upload/files/52765748216.pdf
    • https://mygenius.ru/admin/ckfinder/userfiles/files/41826873668.pdf
    • https://mkycc4.com/kycc4.com/userfiles/files/begaxelitidir.pdf
    • http://fkjz.cn/upload/files/2021/09/202109062325522456.pdf
    • http://teusz.pl/UserFiles/file/85931802367.pdf
    • http://uhorder.com/upload/files/1943768289.pdf
    • http://taixingchem.com/uploadfile/file/20210911010756822.pdf
    • http://twfindia.in/userfiles/files/14583291335.pdf
    • http://tageedesign.com/ssmpt/documents/file/paweluzegorosufosuporug.pdf
    • https://lidiyageorgieva.com/ckfinder/userfiles/files/3700521468.pdf
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1613ada158a34b---41038472737.pdf
    • https://thai-airpark.com/ckfinder/userfiles/files/dexuvifuxaze.pdf
    • https://dongciao.com/uploads/files/202109171805049236.pdf
    • https://medicabg.com/uploads/wysiwyg/files/67499461778.pdf
    • http://detskypohar.cz/upload/file/kemesobuk.pdf
    • https://givemeit.ru/wp-content/plugins/super-forms/uploads/php/files/4444bb39be1378d8a14653640fde6eea/71561223122.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=what+colors+to+mix+to+make+light+purple
    • 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_off0000df8f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDF8F 16792 bytes
font_01_sfnt_off0000f7a6.bin
0f842f471a515961a425829e441a67d196c924cbba225d7ba56fc7923dd40ee7
pdf-font-stream PDF embedded font (sfnt) at offset 0xF7A6 11004 bytes
font_02_sfnt_off00011148.bin
69b5d048159f3b3d32057ce4fffb52f1fb7c097a6715a7af5c87c3aec0c9026d
pdf-font-stream PDF embedded font (sfnt) at offset 0x11148 17432 bytes