Malicious PDF — malware analysis report

Static analysis result for SHA-256 18ac1f41c74de46e…

MALICIOUS

PDF

91.4 KB Created: 2021-09-04 06:23:43 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: c60724c6132eb920f4e5452625c90e49 SHA-1: 5c7d1e8f8f39c70f2c4d58d7f51837d19ddefd7c SHA-256: 18ac1f41c74de46ed8473a95cd337d835f5942f5c002e29d0cdfd15d63434662
156 Risk Score

Malware Insights

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

The file is identified as malicious by multiple heuristics and an ML classifier, with ClamAV detecting it as a phishing trojan. The PDF contains numerous embedded URLs, many of which are hosted on compromised WordPress sites, suggesting a phishing or malware distribution scheme. The presence of 'utm_term' parameters in some URLs indicates an attempt to track user engagement with these phishing lures.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9935

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://ketchas.ru/uplcv?utm_term=student+academic+achievement+questionnaire+pdf PDF link annotation
    • https://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/n4kg484ep46ovhfvhvf6v0kdcr/1648037426.pdfIn PDF document text
    • http://beateromer.com/bilder/file/86918977212.pdfIn PDF document text
    • http://uhli-janmaria.cz/userfiles/file/47464528109.pdfIn PDF document text
    • http://cauthangdep24h.com/upload/files/99835222828.pdfIn PDF document text
    • https://tmtteks.com/files/47434829919.pdfIn PDF document text
    • http://cnmrobotics.com/files/files/67288238531.pdfIn PDF document text
    • http://stomerijindex.nl/images/uploads/jorune.pdfIn PDF document text
    • https://kodeac.com/wp-content/plugins/super-forms/uploads/php/files/3o69q2flttfpp8hqdrgbipd96j/48299233217.pdfIn PDF document text
    • https://monarchwinemerchants.com/wp-content/plugins/super-forms/uploads/php/files/0eea39d133acf6941dae6b7d32070178/29137999872.pdfIn PDF document text
    • http://syuncyoku.jp/upload/file/92214395099.pdfIn PDF document text
    • https://aljazeerahpetroleum.ae/userfiles/files/xakenekiwufemexegusixek.pdfIn PDF document text
    • http://razaviota.ir/basefile/razaviotair/files/41049170402.pdfIn PDF document text
    • https://babetravelling.com/ckfinder/userfiles2/files/9541713402.pdfIn PDF document text
    • http://zamokugrofa.sk/admin/fckeditor/file/liwumoxoxuf.pdfIn PDF document text
    • https://jdlpartnerss.com/userfiles/file/kinamonu.pdfIn PDF document text
    • http://tecresconsolidamentorestauro.it/fck_data/file/pomopopenijek.pdfIn PDF document text
    • http://uhy-th.com/image/upload/files/61710203746.pdfIn PDF document text
    • http://pension-erlkoenig.de/img/editor/file/98716472002.pdfIn PDF document text
    • http://giasuthienphuc.com/Images_upload/files/kifoziwo.pdfIn PDF document text
    • http://botosani.ro/img/uploads/file/kijigafugowometutila.pdfIn PDF document text
    • http://alessandrobelleseveterinario.eu/userfiles/files/35016890624.pdfIn PDF document text
    • http://agriturismofattorialucciano.it/ckfinder/userfiles/files/bopipof.pdfIn PDF document text
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021080611162680554.pdfIn PDF document text
    • http://cctsw.net/whly/up_files/FCK/file/20210820_180114_182.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_off0000ff33.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFF33 11228 bytes
SHA-256: 48cfb3620415ee49a00829cadeff71a58dd28229295b06ae96a76180eafb4c94
font_01_sfnt_off00011921.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11921 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013133.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13133 17788 bytes
SHA-256: 3a1d84fee7dc69febc12dedf9d39518afc843b6e10b593e048332ae3053b4c37