Malicious PDF — malware analysis report

Static analysis result for SHA-256 f4866d5b44358470…

MALICIOUS

PDF

85.9 KB Created: 2021-07-20 09:42:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 53d232c61619a16e8b9bc7930b0caa27 SHA-1: 40efbc3c193d7c87061973ac78864375ed66f740 SHA-256: f4866d5b443584702bd692c65f14587847f571f8590a836b3c4f306bcbebe1ca
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was identified as malicious by ML classifiers and ClamAV, indicating a phishing or malware distribution intent. It contains a link farm with numerous URLs hosted on compromised or disposable domains, likely serving as a lure to redirect users to malicious content. The document body is heavily obfuscated and unreadable, providing no direct clues to its specific purpose beyond the presence of these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://www.colours-of.com/wp-content/plugins/super-forms/uploads/php/files/brubi0obdmmh17hj603sdnvhe6/41161486228.pdf In PDF document text
    • https://btcauction.vn/hinhanh/file/73677343721.pdfIn PDF document text
    • http://newtrierreunion1962.com/clients/6/64/64567561842b0bbd40b956adda0282a7/File/zafukipufavesol.pdfIn PDF document text
    • http://autoshiftbid.com/fckeditor/userfiles/file/8837073636.pdfIn PDF document text
    • http://objetivovender.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607948b3479fb---musesi.pdfIn PDF document text
    • http://bezagsecurity.cz/userfiles/94559019193.pdfIn PDF document text
    • https://www.andrecampbell.ca/wp-content/plugins/super-forms/uploads/php/files/45728227c1c870bc3c8ff7b3b8939971/soketepof.pdfIn PDF document text
    • https://nuevocoach.co.uk/wp-content/plugins/super-forms/uploads/php/files/d9068166a19702e0e4075d0ab08ec030/muvidelipemitebafitan.pdfIn PDF document text
    • https://vnsteeldetailing.com/UserFiles/files/wurakuviluvivemikobemag.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/2da3bb7e7a1186a9eabd091be594f413/rikawuvuxabetedulevome.pdfIn PDF document text
    • http://www.restorationservice.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160c4682f39603---91466593045.pdfIn PDF document text
    • https://endoaccessories.com/wp-content/plugins/super-forms/uploads/php/files/u4ia9ua11cbm320535a85l44mn/88311421258.pdfIn PDF document text
    • https://cvsc.co/userfiles/file/sogosixilo.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160703fc9445ac---tenazavini.pdfIn PDF document text
    • https://bodegoncriollo.com/userfiles/file/vubanipore.pdfIn PDF document text
    • https://teenvolunteer.org/wp-content/plugins/super-forms/uploads/php/files/da741ceb957ffdbb3c72f9f29d0fe85c/pokiwebobolorojosuga.pdfIn PDF document text
    • http://www.thelawchamber.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c5fbf02848d---gaferodafawi.pdfIn PDF document text
    • http://medicaldistri.com/ckfinder_files/files/99624421552.pdfIn PDF document text
    • http://svenstavik.com/wp-content/plugins/formcraft/file-upload/server/content/files/160780dd541e17---36197077585.pdfIn PDF document text
    • http://tuclubcr.com/campannas/file/94693117860.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/a2a4abad1f2d7fb4885d797c69c5f00e/fudukanijew.pdfIn PDF document text
    • http://msamericapageant.com/clients/873634/File/43609888697.pdfIn PDF document text
    • http://www.nuricomuvakfi.org/wp-content/plugins/super-forms/uploads/php/files/mo7vcd4oupltv283vql74ntkl4/sajijivexe.pdfIn PDF document text
    • https://carthink.org/wp-content/plugins/formcraft/file-upload/server/content/files/160796e74f3b80---mijunupukiwi.pdfIn PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c150910c68d---bapugasivom.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/DOqCt-cVA4I/uplcv?utm_term=how+many+calories+in+a+cup+of+self+raising+flourPDF 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_off0000eb37.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB37 17264 bytes
SHA-256: 71028347cc9d0f8da2e5ce6b774525f1567ee230a398b367812bf421157c0d47
font_01_sfnt_off00011834.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11834 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001304b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1304B 11016 bytes
SHA-256: 10bab3fabac110bdf5e44ac770ad964e71f8579df64228b8fab7178f10f7a2bb