Malicious PDF — malware analysis report

Static analysis result for SHA-256 acaef25e10f5345d…

MALICIOUS

PDF

75.4 KB Created: 2021-07-18 14:04:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 728edf9c485cf2837f69879607cdc2b2 SHA-1: 2b1c5a4ca063c73d357a5bd1cf4c4e507a9b24ec SHA-256: acaef25e10f5345d3420956bca058cbac9e4779f27ef8af2669d508d33d1fc65
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious. Heuristics indicate it functions as a link farm, directing users to compromised WordPress uploads and other disposable hosting sites. The embedded URLs and the overall structure suggest an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9971

Heuristics 6

  • 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 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://akproauto.com/nbloom/fckuploads/file/3040980228.pdf
    • http://mmdplus.com/userfiles/files/20210619_055426.pdf
    • http://ecohouse-lab.com/userfiles/file/fuwuxewevaludoragan.pdf
    • http://isagenixmakessense.com/ckfinder/userfiles/files/winatekesonuledosuve.pdf
    • http://bronia.org/userfiles/file/75553439237.pdf
    • https://rpdev.org/ckfinder/userfiles/files/48973466814.pdf
    • https://admonks.ru/wp-content/plugins/super-forms/uploads/php/files/b70220746ed2661cb1e9fa3cac0aed9f/54060437544.pdf
    • https://nazragame.com/calisma2/files/uploads/lusibonutonupikefa.pdf
    • https://alsterparkett.de/wp-content/plugins/super-forms/uploads/php/files/ntkdm3hiju08raak6tlt0ghh1b/rilididefamonipaxezajaxut.pdf
    • http://paradisoseminatrici.it/userfiles/files/68800279932.pdf
    • http://kolaykanal.com/userfiles/files/10720944493.pdf
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ee483e2317b---34528454570.pdf
    • http://cobansut.com/userfiles/file/59903976983.pdf
    • http://opakowania-loga.pl/zdjecia/fotki/file/62824134697.pdf
    • https://99shayari.in/userfiles/files/lizibodaliwojobopavojiba.pdf
    • https://beachesbrewing.com/wp-content/plugins/super-forms/uploads/php/files/7a601b616d2797ab86bd09517737d661/33972585529.pdf
    • https://qualitycountscleaning.com/wp-content/plugins/super-forms/uploads/php/files/3d5c2c2dfc9240e4e6643ea38c19b961/28464324688.pdf
    • http://rheumatology.institute/upload/content/file/nosisidinotonevuxaburefar.pdf
    • https://agatanorek.com/files/file/74199062033.pdf
    • http://bazis-expertiza.ru/ckfinder/core/connector/php/files/65713217792.pdf
    • https://bd-sokolovska.eu/userfiles/file/vimibamorisolamudizeguma.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/1KS0DP0cxss/uplcv?utm_term=styxboat+on+the+river
    • 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_off0000c6ab.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xC6AB 16792 bytes
font_01_sfnt_off0000dec2.bin
dd56829abd9a008699b2e9b6976ee6ca24ec81bbcba715689927102dda923e75
pdf-font-stream PDF embedded font (sfnt) at offset 0xDEC2 10488 bytes
font_02_sfnt_off0000f6a3.bin
2f2cbf94b061aec3f36a153b1d9074120e43750770f8350af19765f4f08fb54e
pdf-font-stream PDF embedded font (sfnt) at offset 0xF6A3 16348 bytes