Malicious PDF — malware analysis report

Static analysis result for SHA-256 91189c1438235f3f…

MALICIOUS

PDF

85.4 KB Created: 2021-09-18 08:19:32 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 6c9b90bc4f367b2952ff139459aa69ed SHA-1: 0891509405683b075ce403c70333bf39cda9febe SHA-256: 91189c1438235f3f5f0f43e6f1ac6d9055606b0460fb9f5f5054fcce622c0821
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, many pointing to compromised CMS upload directories or disposable hosting, indicating a likely attempt to redirect users to malicious content. The ML classifier and ClamAV detection strongly suggest malicious intent. Although no scripts were explicitly extracted, the PDF structure and embedded URLs are indicative of a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://aiaato.com/FileData/ckfinder/files/20210908_F07454A053EE1925.pdf
    • https://trungtamgiasuhcmmq.com/uplaod/quangtri/files/resarilefijuxevaxonaku.pdf
    • https://drrajanmahtani.com/userfiles/files/1934240542.pdf
    • http://crocepadrekolbe.it/userfiles/files/7991041247.pdf
    • http://www.kidnuri.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141bb2acc6da---mupafulisu.pdf
    • https://asiquim.com/ckfinder/userfiles/files/tovutako.pdf
    • http://holzbau-napetschnig.at/vubivolotamo.pdf
    • http://www.sunarnuricomuisvealisverismerkezi.com/wp-content/plugins/super-forms/uploads/php/files/s3s3nk418fm4d71c1pij1lqd32/zituvatufalazobipo.pdf
    • http://k12kos.com/ckfinder/userfiles/files/17591739461.pdf
    • http://lovesenergy.nl/file/38847466222.pdf
    • http://yoron.net/up/files/66865276050.pdf
    • http://zit-tech.com/userfiles/files/29888215680.pdf
    • https://www.gsccn.it/wp-content/plugins/formcraft/file-upload/server/content/files/1613ac6f479fdf---674591879.pdf
    • https://inprovitcentroamerica.com/ckfinder/userfiles/files/45648226840.pdf
    • http://taikenplan.jp/ckfinder/userfiles/files/22607995287.pdf
    • http://xecuoihuyhoang.com/uploads/userfiles/file/2824315922.pdf
    • https://eastmangroup.org/ckfinder/userfiles/files/13387876639.pdf
    • http://kfoodntea.com/dataroom/file/86046848444.pdf
    • http://rsentco.com/upload/file/mevadovasodewavodofaf.pdf
    • http://sweet-sugar.de/images/uploadedimages/file/zikolokutojuse.pdf
    • https://petribax.nl/userfiles/file/nodosuvopugobomopesifix.pdf
    • https://myparrotfood.com/user_files/files/wowajojoluk.pdf
    • http://www.slappedtogether.com/editoruploadfiles/file/nilegamuxitupasesu.pdf
    • http://artiguardia.pl/userfiles/file/90612027540.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/ngfLrbzwjls/uplcv?utm_term=relationship+between+velocity+frequency+and+wavelength
    • 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_off0000e1e0.bin
11051b505b0021c7711f8aeb59da1d18a9cf97c4c0460fdf20d36969415db68b
pdf-font-stream PDF embedded font (sfnt) at offset 0xE1E0 11596 bytes
font_01_sfnt_off0000fcae.bin
86c63309dfc6bda4cfc288aa78dfeb444ec481e295c79f2c7e6f4a7a7db5af73
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCAE 19508 bytes
font_02_sfnt_off00012fb9.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12FB9 16792 bytes