Malicious PDF — malware analysis report

Static analysis result for SHA-256 ef61ac5d27aedc87…

MALICIOUS

PDF

68.2 KB Created: 2021-09-28 16:51:14 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-23
MD5: 50b0b625856a61c93acd2c8cba9f1cb1 SHA-1: aff9021c38d95fcdf5fa900edea40b1e0629ed96 SHA-256: ef61ac5d27aedc8758fb715a6311451cd8c80e296e77fd84d135887083265759
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate the document functions as a link farm, directing users to multiple external websites, some of which are hosted on compromised CMS uploads or disposable domains. The embedded URLs suggest an attempt to redirect users to malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://www.hs-hofgastein.salzburg.at/ckfinder/userfiles/files/sulidufen.pdf In PDF document text
    • https://derya.afmiletisimajansi.info/resimler/files/mupobaruribajavakebub.pdfIn PDF document text
    • https://rtquery.reitoken.org/Coaching123/images/files/47573859364.pdfIn PDF document text
    • https://www.wsbe17hongkong.hk/_bin/ckfinder/userfiles/files/92914041544.pdfIn PDF document text
    • https://hse.tw/upload/file/davuvemu.pdfIn PDF document text
    • https://gagiongvitgiong.com/ckfinder/userfiles/files/92387476853.pdfIn PDF document text
    • https://jmbarrenetxea.soinuenea.eus/files/galeria/files/79747868096.pdfIn PDF document text
    • https://demircanticaret.com/userfiles/file/22004925872.pdfIn PDF document text
    • https://sunkamalzemecilik.com/userfiles/file/poforewerariwal.pdfIn PDF document text
    • http://dakmoto.cz/obrazky/file/fenota.pdfIn PDF document text
    • https://magicdiscoradio.com/userfiles/file/63387306598.pdfIn PDF document text
    • https://medosojewellery.com/userfiles/files/68115280710.pdfIn PDF document text
    • http://lactopad.com/uploads/files/53026599899.pdfIn PDF document text
    • http://soosanfix.com/upload/fckeditor/file/wukomoboko.pdfIn PDF document text
    • http://centroolosprato.it/userfiles/files/tufiko.pdfIn PDF document text
    • https://perfecthospitals.com/FCKeditor/file/ripevi.pdfIn PDF document text
    • http://mylodge-naoshima.com/images/blog/file/sozevav.pdfIn PDF document text
    • http://www.infranetltd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16149ea523aa87---8255169424.pdfIn PDF document text
    • http://ontheedgeofnow.com/wp-content/plugins/formcraft/file-upload/server/content/files/16142e4d57ef2a---nuzowug.pdfIn PDF document text
    • http://longruiglass.com/ckfinder/userfiles/files/20210922_161516.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/161433fe64419b---najopitar.pdfIn PDF document text
    • http://xn--j1aii.su/userfiles/file/kovubenofemapukono.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1xuhb7AK25c/uplcv?utm_term=led+with+wifi+price+in+pakistanPDF 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_off0000ac49.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC49 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c460.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC460 10684 bytes
SHA-256: c37652b09c6a3d0141c18017c1196091b389a3eb9fa39814221bf56f37f3e5a7
font_02_sfnt_off0000dce1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDCE1 14708 bytes
SHA-256: cc2d5a504dcace3aceda7dd6fb6a4cd124a893171dc9c0a09d75bab9256013c8