Malicious PDF — malware analysis report

Static analysis result for SHA-256 6c4ebbaa3e555a96…

MALICIOUS

PDF

84.2 KB Created: 2021-06-30 19:30:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 69891b6c09b37b354e6c2cffd3281b10 SHA-1: 6db65a0ea53b42e0888b0904413f1aba88bfafa1 SHA-256: 6c4ebbaa3e555a96174255005fbce318d650758fa1668b4af2de974bccb6007c
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised WordPress sites or disposable domains. The document body is heavily obfuscated and unreadable, suggesting it is not intended for human consumption but rather to host these malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9833

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://garderoba.sk/images/_file/bipovese.pdf In PDF document text
    • http://anandamsanyal.com/userfiles/file/45989856865.pdfIn PDF document text
    • http://fluidearthconcrete.com/userfiles/file/vibilupukilor.pdfIn PDF document text
    • http://mkconline.com/landmark/ckfinder/userfiles/files/vananuton.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1609493f85210b---kadobibadirudamaka.pdfIn PDF document text
    • https://encouragingmath.com/wp-content/plugins/super-forms/uploads/php/files/f802c7c56b682d71e08bc7e8656f1672/52252552608.pdfIn PDF document text
    • https://tvsporedi.si/vsebina/xujaxudutik.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/94898f1c39f28b17dfd7c586f2903f85/40634070558.pdfIn PDF document text
    • https://www.adelaarenergy.com/wp-content/plugins/super-forms/uploads/php/files/fn14bm269hs99c4dr247e8uopr/83309340866.pdfIn PDF document text
    • http://alituncer.com/userfiles/file/gufebigofotusik.pdfIn PDF document text
    • https://stillwaiting.org/userfiles/file/17369399822.pdfIn PDF document text
    • http://midiabyz.com/wp-content/plugins/super-forms/uploads/php/files/180d957dc6606fce5ce2af7b550cc5ba/mufikumeladidarigis.pdfIn PDF document text
    • https://www.ogblfrontaliers.fr/wp-content/plugins/super-forms/uploads/php/files/n2i9uha394vq4m0n5u5dsg33vj/boluxiwofujufavup.pdfIn PDF document text
    • https://acgroupenterprise.com/userfiles/file/dinisamoxamenoxobes.pdfIn PDF document text
    • http://kashima.cc/userfiles/file/wimasikusekurigox.pdfIn PDF document text
    • https://sandzak.best/wp-content/plugins/super-forms/uploads/php/files/ab5c41e373ecb76d5a6b0445cf841562/danomopoxox.pdfIn PDF document text
    • https://humanistbeauty.com/wp-content/plugins/super-forms/uploads/php/files/1ku2vp1h317duf74o64r3lg3mc/63748393200.pdfIn PDF document text
    • http://stellamaris.cz/userfiles/60475103192.pdfIn PDF document text
    • https://www.sadcmedia.com/wp-content/plugins/super-forms/uploads/php/files/jjfs3218tgs3quvhm82bn823i7/46521670713.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/d4beb979d511c86d801c3c0229e5a384/30278901118.pdfIn PDF document text
    • https://drmiamiconnect.com/wp-content/plugins/super-forms/uploads/php/files/be51fe06e0495430bc66ce15b608f5a0/dadew.pdfIn PDF document text
    • https://leicht-spb.ru/wp-content/plugins/super-forms/uploads/php/files/c2c5c8a8140f8c9893f2fc2d8f5cdd67/23825202845.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/16076b12ecd015---16677869027.pdfIn PDF document text
    • http://arlingtonhigh1961.com/clients/e/ef/ef36f0800c0a5d5a0b00d5ecc8c3c6da/File/2787226886.pdfIn PDF document text
    • http://mas.vacations/wp-content/plugins/formcraft/file-upload/server/content/files/16094059d1242c---mopate.pdfIn PDF document text
    • https://www.revistadefiesta.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a0e7212a88a---89520946268.pdfIn PDF document text
    • http://adance0112.com/upfile/editor/file/44469748002.pdfIn PDF document text
    • http://www.stockholmswingallstars.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082de4ca87fb---77868668403.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/S30rS-6n6vg/uplcv?utm_term=game+show+word+search+proPDF link annotation
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#In PDF document text
    • http://purl.org/dc/elements/1.1/In PDF document text
    • http://ns.adobe.com/pdf/1.3/In PDF document text
    • http://ns.adobe.com/xap/1.0/In PDF document text
    • http://ns.adobe.com/xap/1.0/mm/In PDF document text
    • http://ns.adobe.com/xap/1.0/rights/In PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e16b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE16B 10564 bytes
SHA-256: edbc7fd59db91a7a4581234c489f03564b80d4eddedbd9c0597fe3abbf395a3c
font_01_sfnt_off0000f99a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF99A 18112 bytes
SHA-256: e10f102632510394db3d0155a6809bf7e909d744623951409079f10582a55e78
font_02_sfnt_off000129af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129AF 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1