Malicious PDF — malware analysis report

Static analysis result for SHA-256 3558e6ef8ccbd1fb…

MALICIOUS

PDF

87.2 KB Created: 2021-07-02 23:15:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 317d052466a6d8d825b558339b509122 SHA-1: d3df76fcb4a191f733f755a3556bb3e3cc5976bb SHA-256: 3558e6ef8ccbd1fbbd6c8d593b5e25586134475e2ac42d1b24255894cf05e73a
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier indicated a high probability of maliciousness. Heuristics identified it as a link farm, with many URLs pointing to compromised CMS upload directories. The document body is heavily obfuscated and unreadable, suggesting it is not intended for direct user interaction but rather to host links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

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://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/aa14a860bc37cfeb9e7b3679bf4df127/11306462881.pdf
    • http://willtorock.com/wp-content/plugins/formcraft/file-upload/server/content/files/160810e5875ff6---vinolipub.pdf
    • http://antansconstructions.com/ckfinder/userfiles/files/bodudur.pdf
    • http://originalcheck.it/public/img_admin/file///68703358898.pdf
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160769568a6f87---bilakunim.pdf
    • http://fiumevivo.it/userfiles/files/48189313817.pdf
    • http://miraesusan.com/ckupload/files/kizorusepexolibujebipab.pdf
    • https://indacphuc.com/wp-content/plugins/super-forms/uploads/php/files/sooul1qrmri5ms7v9rgim8l7hj/nakivufazutetix.pdf
    • http://alexanderjamesbackcatalogue.com/userfiles/file/35867013981.pdf
    • http://alexanderkanevskyartgallery.com/clientMedia/file/1016912575.pdf
    • https://fmpride.com/wp-content/plugins/super-forms/uploads/php/files/6d7da694e7387eb86f6b98cd4b966ce3/9814150382.pdf
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/160771ddc2dc50---11154841969.pdf
    • http://gazosilikatnn.ru/uploads/files/85558949804.pdf
    • http://galgalesh.com/userfiles/file/gizukowasu.pdf
    • http://itkaufmann.com/images/fckimages/file/sajudodabupuwokomanipi.pdf
    • https://118highschool.am/wp-content/plugins/super-forms/uploads/php/files/772c2074dcef670de41bfc38d051bbd2/31553737500.pdf
    • https://ateneoarbonaida.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c15e555baa7---bulosanibemorosakafikur.pdf
    • http://wsp.pl/userfiles/file/juvopunajejejeloxe.pdf
    • https://bentzendesign.se/wp-content/plugins/formcraft/file-upload/server/content/files/1608ea8fba9f19---48188092411.pdf
    • http://fxmeat.com/upload/file/dd64f03fd317b67f84638c8efe843497.pdf
    • http://smart-ventures.ch/upload/Editor_Images/files/nigawogut.pdf
    • https://dentinale.eu/wp-content/plugins/super-forms/uploads/php/files/956404cd6a15886ce6ce85acd2145549/64567750498.pdf
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/16082428f26314---nemazakade.pdf
    • http://dajuicebarus.com/uploads/files/zonufovoso.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/3CAf4wW3hvY/uplcv?utm_term=water+is+nonpolar
    • 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_off0000f2a3.bin
21b7ecb3d166ea4cbaa4a996d61a94f9c66d15992630cc8a85e2d808ca19a359
pdf-font-stream PDF embedded font (sfnt) at offset 0xF2A3 17096 bytes
font_01_sfnt_off00011f37.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11F37 16792 bytes
font_02_sfnt_off0001374e.bin
5e2280523ff48a6a3f24983d0e7043df87fc0cbe9a215b5b8f082591af0aac10
pdf-font-stream PDF embedded font (sfnt) at offset 0x1374E 10236 bytes