Malicious PDF — malware analysis report

Static analysis result for SHA-256 cbcfaa13ca3e6662…

MALICIOUS

PDF

71.8 KB Created: 2021-09-11 16:59:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: e542494743197d2db811e75b95d25eab SHA-1: 3d6fb84bea05821ac8d4b4adeb75d62d3696660d SHA-256: cbcfaa13ca3e66627e7a55961e6a2cd45b658dd98f0056db4c81472a61c38ab6
156 Risk Score

Malware Insights

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

The PDF was flagged by ML classifiers and ClamAV as malicious, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, with many URLs pointing to compromised WordPress uploads and disposable hosting, suggesting a phishing or malware distribution scheme. No scripts were extracted, but the structure and URL patterns are consistent with a phishing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9986

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 https://optimuselearningschool.aels.edu/learning/site/images/uploadfiles/xawukixifilumakejawod.pdf
    • http://acril.ru/ufiles/files/jedajexesulebafelilixike.pdf
    • http://conservationenergy.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c08b207912---61043096332.pdf
    • http://mtcnx.com/upload/fckimagesfile/62276984400.pdf
    • https://alenakovalchuk.ru/wp-content/plugins/super-forms/uploads/php/files/8fe60d547ee2803744048f4e38730359/44238398683.pdf
    • https://promptcorporate.com/ckeditor/ckfinder/userfiles/files/16928596450.pdf
    • http://polyalpan.hu/_user/file/sexoduwuwaxibesure.pdf
    • http://ahkjt.com/upfile/file/44621459678.pdf
    • https://mdteam.se/ckfinder/userfiles/files/74196903620.pdf
    • https://autosofortkauf.ch/wp-content/plugins/super-forms/uploads/php/files/fcrujsb2q4khiin4algth95mt1/beriduveguzifaluwis.pdf
    • https://slotpt2.com/contents/files/94209205404.pdf
    • http://svazekobciorlice.cz/userfiles/file/52053907232.pdf
    • https://balbok.net/admin/ckfinder/userfiles/files/bunikenabulezawu.pdf
    • http://juncheng.tw/upload/files/76410098710.pdf
    • http://hondasushi.com/uploads/files/gemov.pdf
    • http://www.plain-pied.com/editeur/ckfinder/userfiles/files/sewegugoluxuxamujovotep.pdf
    • http://angerdress.store/ckfinder/userfiles/files/91433193307.pdf
    • https://elitstroycraft.ru/source/file/bajetosa.pdf
    • https://dom4m.de/userfiles/files/limer.pdf
    • https://christianbelieversmatrimony.com/web/christiansbelieversmatrimony/photos/ckeditor/files/68703364840.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/fzgW7-mxBc0/uplcv?utm_term=samsung+galaxy+grand+software+update
    • https://rt9.rspo.org/ckfinder/userfiles/files/zodamapumelediwuvewavejiz.pdf
    • 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_off0000b757.bin
6f88c55f39543ac98a8b5b0e53ee368014e982f8f426fe87e4074e9c58441c8c
pdf-font-stream PDF embedded font (sfnt) at offset 0xB757 11228 bytes
font_01_sfnt_off0000d18a.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xD18A 16792 bytes
font_02_sfnt_off0000e99c.bin
2b73dc27c6f13dc8c02e4f16f85b4443c537df1ecf7f27143b137bdccb2fc246
pdf-font-stream PDF embedded font (sfnt) at offset 0xE99C 15652 bytes