Malicious PDF — malware analysis report

Static analysis result for SHA-256 cd4f0e4dd842e8d6…

MALICIOUS

PDF

72.1 KB Created: 2021-09-02 03:27:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 73c28d412f59cbaee5fd6a4916bd3720 SHA-1: 9d393b2db71e48b7a91f3d605d03cd7b2c6cb5b7 SHA-256: cd4f0e4dd842e8d6efd8a1957884555100154dc191069853dc30d6b45269526c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple distinct hosts, many of which are associated with compromised CMS uploads or disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or malware distribution. Although no scripts were explicitly extracted, the PDF structure and URL patterns are consistent with techniques used to lure users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

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 http://artside.org/data/temp/file/legevodomidenato.pdf In PDF document text
    • https://www.geosuiteonline.de/wp-content/plugins/formcraft/file-upload/server/content/files/16070100e3574d---23168271506.pdfIn PDF document text
    • https://millinerandassoc.com/files/file/88663545607.pdfIn PDF document text
    • https://hmjrgoldhockey.org/wp-content/plugins/super-forms/uploads/php/files/7492d7590a3cc882a319dfd03163aeb2/50448821099.pdfIn PDF document text
    • http://rentbucharest.net/images/userfiles/47694234383.pdfIn PDF document text
    • http://cukiernia-waltar.pl/qcms/userfiles/file/zakaxabig.pdfIn PDF document text
    • https://sardavetri.it/userfiles/file/75467340978.pdfIn PDF document text
    • http://www.examnotice.in/uploads/files/995401757.pdfIn PDF document text
    • https://southernlightingsource.com/wp-content/plugins/super-forms/uploads/php/files/40825a9a3a824655521e3ef70136745c/54085958487.pdfIn PDF document text
    • http://longhornrings.com/clients/0/08/08da48574b41509ac7bedcf2500dc652/File/57766161425.pdfIn PDF document text
    • https://fotokeramika.bg/userfiles/file/damabipobi.pdfIn PDF document text
    • https://astoriareiki.com/wp-content/plugins/super-forms/uploads/php/files/09b696ec4d357b0d62e3912cb5435a27/sofogasetemoliwo.pdfIn PDF document text
    • http://sosnovgeo.ru/userfiles/file/famosagoxefupenog.pdfIn PDF document text
    • http://bkht.vn/userfiles/file/narinedokem.pdfIn PDF document text
    • http://kiko168.com/UploadFile/file/20210826030230363.pdfIn PDF document text
    • https://www.davinci.dk/wp-content/plugins/formcraft/file-upload/server/content/files/160767fbfc0ee8---84418192146.pdfIn PDF document text
    • http://teusz.pl/UserFiles/file/37644415397.pdfIn PDF document text
    • http://whalesart.com/uploadfile/file///2021052818153043.pdfIn PDF document text
    • https://prtl.pl/userfiles/file/kovazomeremuwomiga.pdfIn PDF document text
    • https://gamepinleri.com/calisma2/files/uploads/25977623929.pdfIn PDF document text
    • http://salonlomi.pl/wp-content/plugins/formcraft/file-upload/server/content/files/160b3e3685a46d---butenunutafegu.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/cv9VXjIrmdE/uplcv?utm_term=role+of+producers+in+an+ecosystemPDF 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_off0000b813.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB813 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d025.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD025 16260 bytes
SHA-256: 1e416b21fe385f025415749f5658db58558d4b6d1b98f84136562a1f4591e6e2
font_02_sfnt_off0000f963.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF963 11040 bytes
SHA-256: 1390fa5ca9cc0340adcd69ce13cf09ad03df604619c1ce0ef96ab8650e127f82