Malicious PDF — malware analysis report

Static analysis result for SHA-256 31966358db1876fc…

MALICIOUS

PDF

84.8 KB Created: 2021-07-01 19:48:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 1dad47366797773407f68c80b087772e SHA-1: e35d23c01b312733313695f370fb5549611f3bbe SHA-256: 31966358db1876fc20b3b021ef7680acfe35a8596d8f3b5353a6f0a7cc4f74cc
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

This PDF file was flagged by multiple heuristics as malicious, including a critical ClamAV detection and an ML classifier. It functions as a link farm, containing numerous URLs that point to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. The presence of embedded URLs and the overall structure indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

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 http://change4best.ru/upload/file/93159746902.pdf
    • https://dsodrecital.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bc08b2d4096---3904683975.pdf
    • http://aliglobshop.com/userfiles/file/91089814553.pdf
    • http://oilandgaswork.com/userfiles/file/susitemugomedidelomuw.pdf
    • https://vrindaindia.com/php/joseph/uploads/file/vodixanisogeniveretise.pdf
    • https://massagetheory.ca/wp-content/plugins/super-forms/uploads/php/files/df6f5136f957c6f11383137b263b62c7/virizogaxajupakorufiwelu.pdf
    • http://www.dj-csnl.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160cf7420e4296---58675411996.pdf
    • https://www.oneirishrover.com/wp-content/plugins/super-forms/uploads/php/files/17274af24e04a5ff44639805c623b705/baxijumogewapikelogonuvu.pdf
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160716d150ac50---25963165685.pdf
    • https://kayakbranson.com/wp-content/plugins/formcraft/file-upload/server/content/files/160aa949696c15---66718691827.pdf
    • http://gabortech.com/admin/file/50311224024.pdf
    • http://dabaizhongxue.com/upload_fck/file/2021-5-12/20210512143601701353.pdf
    • https://upchealth.net/wp-content/plugins/super-forms/uploads/php/files/440c74f4b11d9eab84152b52378a0a52/banepusiguzo.pdf
    • https://najlepsze-w-polsce.pl/uploads/83014905032.pdf
    • https://phase1acoustics.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a2d1e077fda---32039500088.pdf
    • http://ekotronic.eu/files/file/palimexegigukale.pdf
    • https://apoc.com.au/wp-content/plugins/super-forms/uploads/php/files/bf506a94a5c2b2af8ed4e0c7de6803ea/38689049577.pdf
    • https://mkting.com.co/wp-content/plugins/super-forms/uploads/php/files/796c8088f91c07d85425854f96854635/2054407588.pdf
    • http://hutergroup.de/userfiles/file/95237097852.pdf
    • https://stillwaiting.org/userfiles/file/zerulezefetidi.pdf
    • https://wsbtitan.com/images/file/2414376602.pdf
    • https://londonvipchauffeur.co.uk/wp-content/plugins/super-forms/uploads/php/files/9daba2fb96d1a5fc678ef77c10ac41f8/bunal.pdf
    • http://rotang.net/userfiles/file/95919784546.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=lucky+day+hack+2020
    • 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_off0000e8b6.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xE8B6 16792 bytes
font_01_sfnt_off000100c8.bin
b3434b286e5a4aa1e073faa527f8b6f1b0fe09d519235ca2a2562243a75cc68e
pdf-font-stream PDF embedded font (sfnt) at offset 0x100C8 17728 bytes
font_02_sfnt_off00012f2f.bin
3da44bfd148858626c43d4eb67e8e3b2ef940716f160a3d702f5a2b70f96751c
pdf-font-stream PDF embedded font (sfnt) at offset 0x12F2F 10112 bytes