Malicious PDF — malware analysis report

Static analysis result for SHA-256 583fbaba3d086d68…

MALICIOUS

PDF

87.0 KB Created: 2021-08-05 06:04:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 89438778c77e09635b5e6604103d6c48 SHA-1: cdb0cdc8d818865f8a0ea211f65007b665df0dc7 SHA-256: 583fbaba3d086d68282c9a3e8024e9a76717c5bbaeced4f2d51f6eeb4cae34de
196 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, and exhibits characteristics of a password-protected archive lure. The document body is heavily obfuscated, but the presence of numerous embedded URLs, many pointing to compromised CMS upload directories or disposable hosting, suggests an attempt to distribute further malicious content. The heuristic 'SE_PASSWORD_ARCHIVE_LURE' strongly indicates the document's purpose is to trick users into decrypting a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9993

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
  • Password-protected archive handoff high SE_PASSWORD_ARCHIVE_LURE
    Document gives password instructions for an archive or attachment — often used to keep payloads encrypted until after gateway scanning
  • 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://bichvan.vn/upload/files/27518939353.pdf
    • http://fzsvybbs.at/userfiles/file/8370817668.pdf
    • https://speak82.com/_UploadFile/Images/file/85675797425.pdf
    • http://www.korayozelguvenlik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b03f12eb156---51073048024.pdf
    • https://aslimitada.com/userfiles/file/94824932205.pdf
    • http://delawaretravelmedicine.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fb59edb877---77265205535.pdf
    • http://cdmvt.cz/sites/default/files/52710509537.pdf
    • http://group-anons.ru/userfiles/files/45702593548.pdf
    • https://m-astar.com/UserFiles/files/23477582021.pdf
    • http://glovimex.com/uploads/ckfinder/files/jopokuge.pdf
    • https://www.hintonassociates.com/wp-content/plugins/super-forms/uploads/php/files/1fdf2f125f13afb6d78f0266a465da42/novifavokubegazanaj.pdf
    • https://dreamscapes.ca/dream_scapes/userfiles/files/38644075793.pdf
    • http://stardentalcare.org/userfiles/file/18751327397.pdf
    • http://studiolauramoschini.it/userfiles/files/lezatopix.pdf
    • https://www.synergyheart2heart.team/wp-content/plugins/super-forms/uploads/php/files/oieof9mm1i9iphb5in369a0a8h/81365301705.pdf
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608183ff8dca2---nababafotuxomamemuv.pdf
    • http://barcabianca.eu/upload/file/lezegatepapix.pdf
    • http://www.39koratmachinery.com/file_upload/files/lokuz.pdf
    • http://enjoy.sk/editor_uploads/system/files/jeweluv.pdf
    • http://www.fullmooneye.com/wp-content/plugins/formcraft/file-upload/server/content/files/160790dc9f264b---neromedetuv.pdf
    • http://poiskvod.ru/images/file/51861783859.pdf
    • http://asustainable.com/global/file/guwixasete.pdf
    • https://feedproxy.google.com/~r/skout/mBVl/~3/ngfLrbzwjls/uplcv?utm_term=the+middleboro+casebook+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_off0000ef6f.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEF6F 16792 bytes
font_01_sfnt_off00010781.bin
afca341b6142d4c046a5ac1f169ef34b12ebb7c244d8c932735fbf6827490577
pdf-font-stream PDF embedded font (sfnt) at offset 0x10781 17576 bytes
font_02_sfnt_off0001350f.bin
a5c18eee272e49102e8100191ea33bc5dbc6e5bfc6ac9295d0982676d5383ab6
pdf-font-stream PDF embedded font (sfnt) at offset 0x1350F 10880 bytes