Malicious PDF — malware analysis report

Static analysis result for SHA-256 a8c145585eb35636…

MALICIOUS

PDF

88.7 KB Created: 2021-09-01 20:23:46 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: c4527fa851d19f8e7d8865ca0b566ddc SHA-1: 3e88a5b9b3162be11744d2de5ab8e52546d55dde SHA-256: a8c145585eb35636f6c5e82427b22ff3f37291645dd9dc96aee668a613ea6d12
184 Risk Score

Malware Insights

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

The PDF contains embedded JavaScript and multiple external URIs, many of which point to compromised WordPress uploads or disposable hosting. These links likely serve as a link farm to redirect users to malicious payloads, as indicated by the ClamAV detection and ML classifier flagging it as a phishing trojan. The embedded JavaScript is likely used to facilitate the redirection or download of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9947

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Clickable URI points to raw IP address medium PDF_URI_IP_LITERAL
    PDF contains a clickable HTTP(S) action whose host is a literal IPv4 address. Legitimate documents normally link to named domains; raw-IP destinations are common in disposable phishing and malware-delivery infrastructure.
  • 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.
  • Embedded JS stream low PDF_JS
    PDF references a /JS stream. Generic JavaScript is common in benign forms; specific dangerous APIs are scored by separate rules.
  • 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://beckydavidsonhomes.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a1e5081f435---33033902067.pdf
    • http://tantos.jp/js/upload/files/65494383932.pdf
    • http://www.radioemka.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083b4bdea508---medozuzi.pdf
    • http://fuzoku-kyujin.jp/ckfinder/userfiles/files/1824417740.pdf
    • https://postscriptproductions.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607bc38d503aa---5290591100.pdf
    • https://bursaceviritercume.com/wp-content/plugins/formcraft/file-upload/server/content/files/160ad53c6321a0---81259533030.pdf
    • http://www.cheapmotorcycleinsurancepa.com/wp-content/plugins/super-forms/uploads/php/files/q2r289621qck4bm0fk6t0hg5r6/mogumuzazomijakosesu.pdf
    • http://alsumiri.net/wp-content/plugins/super-forms/uploads/php/files/c29d08bb9a50282374efa226e0a7a597/duretikumosonusubekome.pdf
    • https://adm.allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/ae328963fed83c4e538dfb3329dcf0e8/mefupubiduwekebuvi.pdf
    • https://cristiandellavedova.com/wp-content/plugins/super-forms/uploads/php/files/d452f348f12fbcd15e95f90065963143/sebidosolikatamodo.pdf
    • https://nhaban24h.com.vn/wp-content/plugins/super-forms/uploads/php/files/g9e1iqo4hdpj5liqv8aukn7rt7/60123523304.pdf
    • http://www.abcklima.hu//data/editorfile/81524601288.pdf
    • http://tensoinox.com/userfiles/files/4785773365.pdf
    • http://157.230.241.115/image/upload/File/34782256114.pdf
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/1609f84e69b8bc---75794161119.pdf
    • http://slhs1958.com/clients/18590/File/zukeximugiv.pdf
    • http://www.fliesen-brill.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b8c64e0c148---vivowerez.pdf
    • https://choiceenergynetwork.com/wp-content/plugins/super-forms/uploads/php/files/1d49f526453a78efd07285dbc95b1b92/miseduxowefogomopegat.pdf
    • https://desertflying.club/wp-content/plugins/formcraft/file-upload/server/content/files/16092e97781c6e---voserezajejajir.pdf
    • http://bonfiremadigan.com/uploads/fckeditor/file/ruwegutejilowidesebu.pdf
    • http://jodhpurtravels.com/nbloom/fckuploads/file/29502056029.pdf
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/160771817e2c33---98133355512.pdf
    • http://aristosaigonhotel.com/uploads/files/35415662354.pdf
    • http://bukhatirhomes.com/userfiles/file/51654853401.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/fzgW7-mxBc0/uplcv?utm_term=schools+giving+out+food+today
    • 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_off0000f79c.bin
9b993a21a74fb0899f2c89cfbd4cdeb168fcdd3b7f526aff5bb974d870325348
pdf-font-stream PDF embedded font (sfnt) at offset 0xF79C 10880 bytes
font_01_sfnt_off00011087.bin
7309ffa70fa2c710c6c5309303de8fe9760ecfaa38ea59b920774976bb15925b
pdf-font-stream PDF embedded font (sfnt) at offset 0x11087 17296 bytes
font_02_sfnt_off00013d3c.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x13D3C 16792 bytes