Malicious PDF — malware analysis report

Static analysis result for SHA-256 e4d2c8321f0f57e3…

MALICIOUS

PDF

77.3 KB Created: 2021-09-08 16:06:16 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: d1755425d9a64009a0ba6999cf0291b2 SHA-1: d8fcbdb3272a2a4261ef6ed50bdb1e17b68389c9 SHA-256: e4d2c8321f0f57e39ce421e9a915b7e8e31bf6c7ad8004d0d56a96f01cc4b5ea
126 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, with heuristics indicating it functions as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or distributing further malware. Although no scripts were explicitly extracted, the PDF structure and embedded links are indicative of malicious activity.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9943

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://smidgel.ru/uplcv?utm_term=disadvantages+of+observation+method+pdf PDF link annotation
    • http://metall-press.ru/files/fudegunagumoz.pdfIn PDF document text
    • http://huarui-bio.com/upload/files/20357188047.pdfIn PDF document text
    • http://www.scenekunstskolen-efteruddannelsen.dk/ckfinder/userfiles/files/pupazugilulapijo.pdfIn PDF document text
    • http://jwconsult2005.com/file_media/file_image/file/migixasilipi.pdfIn PDF document text
    • https://ph2020.org/ckfinder/userfiles/files/67685504397.pdfIn PDF document text
    • http://www.airportlimofortlauderdale.net/wp-content/plugins/formcraft/file-upload/server/content/files/1612f11bc19ce0---60760512247.pdfIn PDF document text
    • http://closehorses.com/userfiles/file/3764792953.pdfIn PDF document text
    • https://vaitinhdien.com/app/webroot/upload/files/zobuxizivi.pdfIn PDF document text
    • http://leicesterbiketec.com/userfiles/file/semidozamox.pdfIn PDF document text
    • https://egyptsuntours.com/userfiles/files/70078265532.pdfIn PDF document text
    • https://shiokuda2.com/contents/files/26820717010.pdfIn PDF document text
    • http://rld-carbon.ru/file/77070576360.pdfIn PDF document text
    • http://peter-crooks.com/userfiles/file/97085414726.pdfIn PDF document text
    • http://2015.letnifestiwal.pl/ckfinder/userfiles/files/sezegisexuderunu.pdfIn PDF document text
    • http://gemmacapitalgroup.com/foto/file/fepetupasafufidibojuzoxaz.pdfIn PDF document text
    • https://holocaustresearch.pl/nowy/photo/file/dixusotiwegubuf.pdfIn PDF document text
    • https://kalashad.com/userfiles/file/39371974470.pdfIn PDF document text
    • https://organicfertilizerproduction.com/d/files/godakimidamalozesuzetev.pdfIn PDF document text
    • http://seibyou-koujien.com/files/files/jozoxebabutitetegujul.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161348cf4c264e---70468143698.pdfIn PDF document text
    • http://instit.ac/ckfinder/userfiles/files/4453016946.pdfIn PDF document text
    • https://xn--90ah6akb9e.xn--p1ai/f/file/19984138644.pdfIn PDF document text
    • https://himalayanespresso.com/espresso_ckfinder/userfiles/files/fotegavedigokudarevonin.pdfIn PDF document text
    • http://citygclub.com/ckupload/files/98841346811.pdfIn PDF document text
    • http://lightofislamonair.org/uploads/files/7786763887.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_off0000cc39.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC39 16376 bytes
SHA-256: 17d99e8ba3505ba570768af1a1ab9f288b3c03c264b91db0108d80070200e48b
font_01_sfnt_off0000f65d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF65D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00010e74.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E74 11104 bytes
SHA-256: 4247bfaf2dee918a47c804cb22c8d2ee2b2fe607efa0345f5512a1f481b7c767