Malicious PDF — malware analysis report

Static analysis result for SHA-256 b6741aa69651f134…

MALICIOUS

PDF

91.7 KB Created: 2021-08-10 22:32:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-24
MD5: 92bd9e43f8480c49d220e99978a195f3 SHA-1: 39bbc6531f6386bf6ca60974e7453d01e085970e SHA-256: b6741aa69651f13476111075d72cffd58c5c166ac7e1cb802c064626be33f383
156 Risk Score

Malware Insights

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

The PDF was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs, many of which point to compromised WordPress sites or disposable hosting, forming a link farm. These links likely serve to redirect users to phishing pages or download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

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://exmar.it/foto_fck/file/wirepewokik.pdf In PDF document text
    • http://gerd-pollak.de/userfiles/file/sezonip.pdfIn PDF document text
    • http://aimecostruzioni.it/userfiles/files/xopejut.pdfIn PDF document text
    • http://coopmong.com/ckupload/files/64188723424.pdfIn PDF document text
    • http://teenmag.cz/userfiles/file/gelakirisipigozisige.pdfIn PDF document text
    • https://www.dartmusicfestival.co.uk/wp-content/plugins/super-forms/uploads/php/files/604da17f3fcaff5a82efad3f8b7acafe/moworubexuxafodezisenaw.pdfIn PDF document text
    • http://www.deep2001.com/images/library/File/41703944180.pdfIn PDF document text
    • https://curvy.tw/upload/files/82226040266.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/565cf8e920ce8fc423cae8edbd279f50/69415484800.pdfIn PDF document text
    • http://dichvu12h.net/userfiles/file/52628780676.pdfIn PDF document text
    • https://veglifekc.org/wp-content/plugins/super-forms/uploads/php/files//85629343674.pdfIn PDF document text
    • https://shiokuda2.com/contents//files/82569129431.pdfIn PDF document text
    • http://angelescare.com/userfiles/file/74139084944.pdfIn PDF document text
    • https://braviengenharia.com.br/wp-content/plugins/super-forms/uploads/php/files/acm3mtenjunnt76uvhda6t888i/87568237698.pdfIn PDF document text
    • https://remoteyourstaff.com/calisma2/files/uploads/13999421802.pdfIn PDF document text
    • https://deepankarbasu.com/FCKeditor/file/43751798288.pdfIn PDF document text
    • http://shinserviceodi.ru/wp-content/plugins/super-forms/uploads/php/files/0e516c209a47c1a7ade666610cf85ec5/14650468244.pdfIn PDF document text
    • http://www.shipsupply.co.mz/wp-content/plugins/formcraft/file-upload/server/content/files/160a356d00205c---boxonomozojobinanetarutub.pdfIn PDF document text
    • http://geobigoni.it/userfiles/files/xexuwokujitiji.pdfIn PDF document text
    • http://p-energo.ru/content/file/20928193272.pdfIn PDF document text
    • http://sanitaerprofi.ch/fckeditor/editor/images/file/72615871904.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/LPIa9PGmDLg/uplcv?utm_term=how+to+find+out+child+support+balance+floridaPDF 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_off000100a2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100A2 17680 bytes
SHA-256: cbffa0e7d634877c0b03f688fc7176105e3d71c9101b278d20df7f3550c51e79
font_01_sfnt_off00012e9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E9A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000146b1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x146B1 11036 bytes
SHA-256: 4ea85d2f1c67150130bbf38956a785cbd2b77db488dfab282743edafb01fd013