Malicious PDF — malware analysis report

Static analysis result for SHA-256 de37b69fc350ec54…

MALICIOUS

PDF

76.6 KB Created: 2021-06-25 16:43:47 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 9f4f0fc44767a054009da07f8edf8241 SHA-1: 7f045d92e4aafb163f8cdd37572f83caeed703d0 SHA-256: de37b69fc350ec54516a46d44019ad52d27224f881f9ceb52e0340b46c9a0232
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link

The PDF contains numerous links to external websites, many of which are hosted on compromised WordPress installations or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. No scripts were extracted, and the document body was unreadable, so the analysis relies on the URL heuristics and AV detection.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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://infrive.ru/uplcv?utm_term=tips+to+spend+less+money
    • https://open-call.fr/uploaded/files/69100876417.pdf
    • http://c2mag.com/wp-content/plugins/formcraft/file-upload/server/content/files/1606f2616c6c05---fesurugote.pdf
    • https://www.lang-mayer.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b91adc82d0e---55612221113.pdf
    • https://wills.sg/wp-content/plugins/super-forms/uploads/php/files/a5e6b7f89c9025ac15f8d2406ed0b4a6/97469222515.pdf
    • https://www.auditek.fr/wp-content/plugins/formcraft/file-upload/server/content/files/16086fc25e77d2---62427487264.pdf
    • http://anthonyvienna.com/sites/default/files/file/pigiladalex.pdf
    • http://wchs65.org/clients/b/bb/bb65574a37642f7fe3135935df861e67/File/43290953007.pdf
    • https://akdenizokullari.k12.tr/wp-content/plugins/super-forms/uploads/php/files/al0hfp67e6ofp6ru4hu1l8s34f/54475475487.pdf
    • https://torrentclub.vip/wp-content/plugins/super-forms/uploads/php/files/2g5l2k9oe0dutl34bi9ndvgrmg/56860631978.pdf
    • http://asustainable.com/global/file/78739894207.pdf
    • http://ggmtc.net/userfiles/files/dukojolugirik.pdf
    • https://rhagro.com.mx/wp-content/plugins/super-forms/uploads/php/files/9c13aa8b6a9707f36da403ce70532e30/porelexuguxekoz.pdf
    • https://youstore21.com/wp-content/plugins/super-forms/uploads/php/files/e9a45364df4a2d6fffb16db16ff4ec1f/mubedametoxosonodewunupa.pdf
    • http://asbufestival.com/uploads/FCK_files/file/zaperi.pdf
    • http://autoscuolavalerio.it/userfiles/files/16621162827.pdf
    • http://ty-universe.com/image/files/20210621_062657.pdf
    • http://exosportsante.fr/ckfinder/userfiles/files/16546909104.pdf
    • http://www.kissdocs.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160848e6151455---varorafow.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000b583.bin
cd4f70d6b579a4c85fdd71bd29242be397c2292a2174412d56f2b052f8976c88
pdf-font-stream PDF embedded font (sfnt) at offset 0xB583 10368 bytes
font_01_sfnt_off0000ccf5.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCCF5 16792 bytes
font_02_sfnt_off0000e507.bin
43f79c6a2bf5f3035d2d05440ee61da4998a09ab0b6725356d1ed8e2a46aa5d5
pdf-font-stream PDF embedded font (sfnt) at offset 0xE507 16172 bytes
font_03_sfnt_off00010e36.bin
c26743b87dfacdf0858f4b0a7ceb4ab939aa0c8d2a68f1ccae901a3bec0cb177
pdf-font-stream PDF embedded font (sfnt) at offset 0x10E36 16488 bytes