Malicious PDF — malware analysis report

Static analysis result for SHA-256 871b531417efc010…

MALICIOUS

PDF

70.9 KB Created: 2021-06-30 10:12:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: f6fde0ab52e425c50ad194e69bc56058 SHA-1: 40370902a114db433da8f9da9d1d85569a0ec8c0 SHA-256: 871b531417efc010bea8eaf74663c9e311f4b775dde40449370244f39ed4e9c3
156 Risk Score

Malware Insights

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

The PDF file was detected as malicious by ClamAV and an ML classifier, indicating a phishing or malicious intent. It contains a large number of embedded URLs, many of which point to compromised WordPress upload storage, suggesting it's designed to lead users to malicious content or phishing sites. The presence of a link farm on disposable hosting further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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://verandapattaya.com/userfiles/files/mowoxolulakixug.pdf In PDF document text
    • https://keluargamimpi2.com/contents//files/kijopu.pdfIn PDF document text
    • http://nutranghongngoc.com/media/ftp/file/tajimokobumazinubajufe.pdfIn PDF document text
    • http://vtracauto.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607aa3f94d1f9---13155326613.pdfIn PDF document text
    • https://egyiksem.hu/uploads/file/44717159564.pdfIn PDF document text
    • http://littlepearlbooks.in/data/eimages/file/jigobasekawoguxuzozuvowo.pdfIn PDF document text
    • http://wintec-samu.hu/uploads/files/1672158818.pdfIn PDF document text
    • http://claudiodauelsberg.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160980a35bd04c---xutapepiwakeja.pdfIn PDF document text
    • https://amirep.com/wp-content/plugins/super-forms/uploads/php/files/540cdf6037a61b6203238cd9ff97168a/nunadesutoxan.pdfIn PDF document text
    • https://www.servicioscalibrados.com/wp-content/plugins/super-forms/uploads/php/files/21181ba832dd5b0db9704fa7eb776e9e/jawolasujukimaxiv.pdfIn PDF document text
    • https://aawyx.com/sites/default/imageuser/file/75156242563.pdfIn PDF document text
    • http://conwaychristian.org/wp-content/plugins/formcraft/file-upload/server/content/files/16074b22f6c2fa---pumebilixuxofovabezud.pdfIn PDF document text
    • http://fmi.lu/userfiles/files/65901581857.pdfIn PDF document text
    • http://cedule-plachty.cz/files/file/59460513793.pdfIn PDF document text
    • http://pck.malopolska.pl/wp-content/plugins/super-forms/uploads/php/files/12fba9a19cc13c2b873bb39148fb9496/fesevumo.pdfIn PDF document text
    • http://softtox.com/new/userfiles/file/32595840776.pdfIn PDF document text
    • https://securitydm.rs/slicice/file/2200415277.pdfIn PDF document text
    • http://forter.vn/hinhanh/file/76319734899.pdfIn PDF document text
    • http://aarogyamedico.com/userfiles/file/63770766736.pdfIn PDF document text
    • https://amiablediamonds.com/wp-content/plugins/super-forms/uploads/php/files/979472a47115464c8d71b8592773a9e5/82863026299.pdfIn PDF document text
    • https://www.pennlighting.com/wp-content/plugins/super-forms/uploads/php/files/21140dcf3e30dfd6adfed5e210b0d4bd/zuvudakalitinewujijatata.pdfIn PDF document text
    • https://myphi.biz/nbloom/fckuploads/file/74511627821.pdfIn PDF document text
    • http://haiphongcontest.com/images/files/kelosabogogilagabowite.pdfIn PDF document text
    • https://www.isgs.org/wp-content/plugins/super-forms/uploads/php/files/1cc4116318238831b7b6bd5140d348d3/devasexafoniven.pdfIn PDF document text
    • http://sahamit.net/userfiles/file/xorekeninesisapevaluxeg.pdfIn PDF document text
    • https://baxsporthorses.com/userfiles/file/wimidinulevimowogise.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=pin+money+definitionPDF 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_off0000ba67.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBA67 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d279.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD279 15056 bytes
SHA-256: d96587cc23a462eacddfeba3a6d5765f8e1efcfea053be5744cef61291cbdf18
font_02_sfnt_off0000f8c3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8C3 10156 bytes
SHA-256: 6e477c8ee583b5304ec9104f75c0accc044ca8b4b90b05c963d1b50ce43007b5