Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3c283deda1737de…

MALICIOUS

PDF

70.3 KB Created: 2021-09-27 10:02:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 1704eac47a2693a99d1d8140ea29ee49 SHA-1: f8a878241458035943b4acebe116d48900dd3f92 SHA-256: f3c283deda1737dea158b520543e8b1b250aa666fb74615d264969650f6621f3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to disposable hosting or compromised CMS uploads, indicating a link farm designed to distribute malicious content or phish users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or malware delivery via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

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://cructi.ru/uplcv?utm_term=formula+for+nth+partial+sum PDF link annotation
    • http://poltinik.ru/userfiles/file/63336570509.pdfIn PDF document text
    • http://bluebossa.pl/files/file/66617829761.pdfIn PDF document text
    • http://com123.vn/uploads/file/dilebokagejolusito.pdfIn PDF document text
    • http://goang-hann.com/uploads/files/202109111338232295.pdfIn PDF document text
    • http://wsystem.sk/userfiles/files/kilutilot.pdfIn PDF document text
    • http://dermatologomiguelgallego.com/miguel/fck/file/49780782929.pdfIn PDF document text
    • https://kolkataangikar.org/ckfinder/userfiles/files/fudaduwewodapijib.pdfIn PDF document text
    • http://erpsamik.com/ckfinder/userfiles/files/36220771733.pdfIn PDF document text
    • http://inlovehuahin.com/file_media/file_image/file/69091500517.pdfIn PDF document text
    • https://www.seblocation.com/ckfinder/userfiles/files/veruribo.pdfIn PDF document text
    • http://conflictfreeelectronics.com/ourprojects/chowki/UserFiles/renuka/file/6926730.pdfIn PDF document text
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/1615151c8e0974---562455331.pdfIn PDF document text
    • https://gallerylingard.com/uploads/file/ravutatogajogikago.pdfIn PDF document text
    • http://unibox.lv/files/text/liwezifudotufub.pdfIn PDF document text
    • https://247christianity.org/fckeditor/userfiles/file/225952755101631575323.pdfIn PDF document text
    • http://papianiarch.it/userfiles/files/bupogetinapigiru.pdfIn PDF document text
    • http://kowalstwwo.pl/public/cms/images/file/69516943591.pdfIn PDF document text
    • http://trivio.it/userfiles/files/rinowoturukovufufixuf.pdfIn PDF document text
    • https://nnkcreations.com/userfiles/file/43863116912.pdfIn PDF document text
    • http://amirafouad.com/uploaded_files/file/93300724750.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613707b039892---1344579853.pdfIn PDF document text
    • https://nuregio.de/wp-content/plugins/formcraft/file-upload/server/content/files/161450d4b52251---29486864262.pdfIn PDF document text
    • http://redactron.com/userfiles/file/fevorofakabipunor.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_off0000b2bb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB2BB 10568 bytes
SHA-256: b43d8050263ec8c672d6c4c2eace013d01ca4284db79423496d56cd96bc6aa2d
font_01_sfnt_off0000ca91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCA91 16156 bytes
SHA-256: f31630af1ffb790874d4d8b597da1c086c524bde6bace77b54b86619981c9830
font_02_sfnt_off0000f36a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF36A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1