Malicious PDF — malware analysis report

Static analysis result for SHA-256 55cca4d1e4434c68…

MALICIOUS

PDF

86.2 KB Created: 2021-06-28 16:53:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 39895dfff90e8209e77bca4a6ac3f8ee SHA-1: beb1ec82a8e67a062896afaec40796c05d001108 SHA-256: 55cca4d1e4434c689d322cd4f7c1c5d283dea7ffe91fc23fc6931c2d90e331be
156 Risk Score

Malware Insights

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

The sample was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier, indicating malicious intent. It contains numerous links to compromised WordPress upload storage and other disposable hosting sites, suggesting a link farm designed to redirect users. The PDF structure and heuristic firings point towards a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9944

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://stewsites.com/wp-content/plugins/super-forms/uploads/php/files/662f10cf3c134b3ae5a1a1fed39b089e/litezigibavunibalisojuz.pdf
    • https://kamarkosong.com/contents//files/godeg.pdf
    • http://acpiindia.com/userfiles/file/97187137148.pdf
    • http://innospectrum.eu/hirlevel/file/mipejajan.pdf
    • https://fieldofgreen.com/wp-content/plugins/super-forms/uploads/php/files/65eb1d92c1d458403fcb5c71ca7f55d0/losanupewo.pdf
    • https://maloneslandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d22957a0a88---11938384232.pdf
    • https://syntellect.ru/Repository/file/bejasipiwuba.pdf
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/160735170e6db6---41052030882.pdf
    • http://rufullthrottle.com/wp-content/plugins/formcraft/file-upload/server/content/files/16078072474088---5769755113.pdf
    • http://dentherapia.hu/files/file/3906823101.pdf
    • http://imreelectric.sk/uploads/file/bukufulebijofoxenexagipi.pdf
    • http://tasarimak.com/ckfinder/userfiles/files/fovixitobilibomuletafolej.pdf
    • https://hoffmanowska.pl/wp-content/plugins/formcraft/file-upload/server/content/files/16090255c9750e---1895441676.pdf
    • https://itexpertdog.com/upload/files/12194884694.pdf
    • http://szyuangang.com/UserFiles/file///foluzexofofepo.pdf
    • http://smithandfriendsfamilyreunion.com/clients/d/d0/d05d9bb0b75700e7199fc64e52c62161/File/56094043909.pdf
    • http://gphs84.com/clients/866382/File/petokelelenusugokinepozin.pdf
    • https://storage-in-motion.com/wp-content/plugins/formcraft/file-upload/server/content/files/16075e534e3066---86885542759.pdf
    • https://remoteyourstaff.com/calisma2/files/uploads/wetikenubala.pdf
    • http://webscape.co.bw/wp-content/plugins/formcraft/file-upload/server/content/files/160cc7ebd0cd91---94437156904.pdf
    • https://canadiancontractorservices.com/wp-content/plugins/super-forms/uploads/php/files/nh49bjmksnu4tpenufokdmil42/87630298839.pdf
    • http://elementsgogreen.com/userfiles/file/jebofi.pdf
    • https://feedproxy.google.com/~r/Uplcv/~3/FevRqgeaUVY/uplcv?utm_term=efficiency+of+riveted+joints
    • 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_off0000d5d9.bin
6e13fcd64c33039c750940837a4bd3115c8bcfc85e0af0d55443cd316583a49a
pdf-font-stream PDF embedded font (sfnt) at offset 0xD5D9 10556 bytes
font_01_sfnt_off0000ee03.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xEE03 16792 bytes
font_02_sfnt_off00010614.bin
505f1f16fb057e2a34e7666bb0a43a50f2e0b7bc0033e59b70183295ac12d2e9
pdf-font-stream PDF embedded font (sfnt) at offset 0x10614 16100 bytes
font_03_sfnt_off00011b4c.bin
92ade0cd80078d754d9a1e67495fb910236eddd818672036118737aa20bbbfab
pdf-font-stream PDF embedded font (sfnt) at offset 0x11B4C 17552 bytes