Malicious PDF — malware analysis report

Static analysis result for SHA-256 3855cd1273e03273…

MALICIOUS

PDF

92.0 KB Created: 2021-08-10 18:16:28 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: 0d9ee978e5e8247ab20eca61720effa5 SHA-1: 59e52d1b6997fa1040b828d9594db057dfafcac6 SHA-256: 3855cd1273e0327324da019a50bf9b433377912ccb63059bddc1f7f5790225e7
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains numerous external URIs and points to compromised WordPress upload storage, suggesting it functions as a link farm to distribute malicious content. The PDF structure and embedded links are indicative of a phishing or malware delivery campaign, likely initiated via spearphishing.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://krisoc.ru/uplcv?utm_term=ess+ia+examples PDF link annotation
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082569baaffd---wagexadarajubororodez.pdfIn PDF document text
    • https://gaseg.com/wp-content/plugins/super-forms/uploads/php/files/uav5f63bh4e9ap6vuqfvf34llc/fojubopivisuworabomuxeres.pdfIn PDF document text
    • https://hkbca.org/UploadFiles/file/20210608142145100.pdfIn PDF document text
    • http://www.alex-vasilkov.ru/images/wisdom/file/tikureduwituweju.pdfIn PDF document text
    • http://adimhukuk.com/resimler/files/61239858039.pdfIn PDF document text
    • https://www.gasserbush.com/wp-content/plugins/super-forms/uploads/php/files/3e534b8f070b0ce56f71b0882e134690/82017248955.pdfIn PDF document text
    • http://www.cascinasorigherio.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607fe9904af16---pupuzotogitisoretis.pdfIn PDF document text
    • http://vivo-mebel.ru/upload/file/86535931246.pdfIn PDF document text
    • https://www.dishdivvy.com/wp-content/plugins/super-forms/uploads/php/files/ce170c90c3f2c6345dc5be21a7c56c0a/jisitegifenowal.pdfIn PDF document text
    • http://foto-preiss.at/upload_files/files/xamovuzo.pdfIn PDF document text
    • https://www.birdandwildlifeteam.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607ea5ae847df---biwiruxosuxowabamoz.pdfIn PDF document text
    • https://allianceflooring.net/wp-content/plugins/super-forms/uploads/php/files/ab38b924728d7fcd7a2d8bc2c3d03ff0/pesujamiteriluganela.pdfIn PDF document text
    • https://www.temsilcisitesi.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607e165c7591d---zajotujufu.pdfIn PDF document text
    • http://www.insurancedirectcanada.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160ce9e0b6456c---64855697507.pdfIn PDF document text
    • http://sjhrz.com/images/upload/File/jijidonetuxu.pdfIn PDF document text
    • http://dmn.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1608746e90b27c---80367173236.pdfIn PDF document text
    • https://showdetango.com/bafa/userfiles/file/74318243408.pdfIn PDF document text
    • http://learnersdigest.org/userfiles/file/21351328516.pdfIn PDF document text
    • http://siciny.pl/userfiles/file/53216121927.pdfIn PDF document text
    • https://cambodiaangkorhomestay.com/userfiles/file/49686651763.pdfIn PDF document text
    • https://cargotavio.ru/files/file/40668399725.pdfIn PDF document text
    • https://alkhairi.co.uk/wp-content/plugins/super-forms/uploads/php/files/8fa2b20bc95c673ba79ebb2bb3e65c5b/44574997418.pdfIn PDF document text
    • 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_off00010587.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10587 10076 bytes
SHA-256: f78a0ede73228a4a8fd6cec0a39fb2ff0668391dfe04d6dba211828c9f1ce383
font_01_sfnt_off00011be9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BE9 17392 bytes
SHA-256: efe6df8ceae893175501aa4ba7608a556de43310445e6712a1c0457147f392ee
font_02_sfnt_off000149cb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x149CB 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1

Open this report in the interactive analyzer, or submit your own file for analysis.