Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c4bf359102ae141…

MALICIOUS

PDF

84.4 KB Created: 2021-07-21 05:11:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 4c721de909513ee56d7bc97b6249ba31 SHA-1: 8c5fb6723cb12bcdbe42bc3a8f0882931d11a554 SHA-256: 4c4bf359102ae1412b3c7c924b3460f52acdf786057a25e582889ef1988edc48
176 Risk Score

Malware Insights

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

This PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It functions as a link farm, containing numerous URLs pointing to external sites, some of which are hosted on compromised CMS upload directories. The presence of multiple links and the use of disposable hosting suggest an attempt to distribute malicious content or conduct phishing operations.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 7

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://maydongy.com/wp-content/plugins/super-forms/uploads/php/files/065jtebja923pgovi2e10jhbo1/wuregisarululasajuzojase.pdf In PDF document text
    • https://www.kngroup.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b8a2b4524c2---jazamililigufixefovi.pdfIn PDF document text
    • https://kvkumariajnkvv.org/singhania/downloads/file/60038696728.pdfIn PDF document text
    • https://aprilboya.com/userfiles/file/voxogigizu.pdfIn PDF document text
    • http://www.mediacomriccione.it/wp-content/plugins/formcraft/file-upload/server/content/files/1609eb6c1d657a---53703649753.pdfIn PDF document text
    • https://vinamex.info/uploads/news_file/52640647122.pdfIn PDF document text
    • https://shinyjewellers.com/wp-content/plugins/super-forms/uploads/php/files/berqlg3hsrkqmgqf3d0atoaqun/17888826776.pdfIn PDF document text
    • http://bethelhanberryaaa.com/clients/2/24/2465ef4bb9bb1b7382310ae17d7cafeb/File/nexutegugizi.pdfIn PDF document text
    • https://klcmekatronik.com/ckfinder/userfiles/files/pudexogoliwug.pdfIn PDF document text
    • https://www.truegridpaver.com/wp-content/plugins/super-forms/uploads/php/files/614cf2fe09c5972dad91ba8d6c762bbb/lonaxikekusisopafobut.pdfIn PDF document text
    • http://haniltm.kr/upfiles/editor/files/23204175579.pdfIn PDF document text
    • https://www.espymetcalf.com/wp-content/plugins/formcraft/file-upload/server/content/files/160da2d4804541---48584196875.pdfIn PDF document text
    • http://dichvugiayphep.net/hinhanh_fckeditor/file/rukevif.pdfIn PDF document text
    • http://www.garriagricola.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607fed6c22b13---63266561608.pdfIn PDF document text
    • http://unipell.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160b24ecae1276---36504707649.pdfIn PDF document text
    • https://doitsolutions.co/wp-content/plugins/super-forms/uploads/php/files/fee464657e908e9d8f6c3e5a1bdab19a/fuvotezimegem.pdfIn PDF document text
    • https://vdbergelectro.nl/wp-content/plugins/super-forms/uploads/php/files/44f95fa8f3537b5085be911e4c8e5eeb/66203132348.pdfIn PDF document text
    • http://donkaew-furniture.com/ckfinder/userfiles/files/77160875710.pdfIn PDF document text
    • http://2ds-creations.fr/userfiles/file/19921202270.pdfIn PDF document text
    • http://www.cafeinca.com/img/public/contenido/file/27547410533.pdfIn PDF document text
    • http://omniatel.it/wp-content/plugins/formcraft/file-upload/server/content/files/160b3d1e164b05---14332380330.pdfIn PDF document text
    • http://wojno-stal.pl/pliki/file/28341410216.pdfIn PDF document text
    • https://dispomydeal.com/wp-content/plugins/super-forms/uploads/php/files/cdb16105bbabc59e280c41a8247152a8/28701324635.pdfIn PDF document text
    • http://auksozvynas.lt/userfiles/file/rirewumeronadezuvi.pdfIn PDF document text
    • https://jahanchart.ir/data/files/file/lenekokosubub.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=have+a+great+night+meaningPDF 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_off0000e968.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE968 10276 bytes
SHA-256: e631ccfa0652c189685caa9455a77d3ebeba0a499e6e630781917498adf2e1ac
font_01_sfnt_off0001003b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1003B 16780 bytes
SHA-256: 569a57a070b0dd23c4ffccfe11d25d33171131f483dc75baf18cad1467ba7f32
font_02_sfnt_off00012c2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C2A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1