Malicious PDF — malware analysis report

Static analysis result for SHA-256 811554e2fc7803b3…

MALICIOUS

PDF

89.2 KB Created: 2021-09-14 07:16:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-12
MD5: cc851f0f18d816e3b3798c925ffd2726 SHA-1: 51bbe08fbca28dff66ad2ec2259e0ffd5b38e3f1 SHA-256: 811554e2fc7803b3c1071945cc7980b303da47eb865d9b081af478f36c4b511e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links, many pointing to compromised CMS uploads or disposable hosting, suggesting a link farm designed to redirect users. The primary attack pattern involves directing users to potentially malicious external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://holzbau-napetschnig.at/25274737208.pdf In PDF document text
    • http://tulga.ru/editor/files/59131595465.pdfIn PDF document text
    • http://www.liveartsaskatchewan.com/wp-content/plugins/formcraft/file-upload/server/content/files/16139df3b46744---7737813669.pdfIn PDF document text
    • https://www.taxiserviceh24.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613bf95e14f08---21861180196.pdfIn PDF document text
    • https://ruxthai.com/ckfinder/userfiles/files/borirorejutasodegolux.pdfIn PDF document text
    • https://wheelmartthailand.com/image/upload/File/gorabezoludofemunowe.pdfIn PDF document text
    • http://theprofitnesstrainers.com/userfiles/file/52527319906.pdfIn PDF document text
    • http://bibliotekaludwin.pl/img/upload/files/4080224438.pdfIn PDF document text
    • http://www.elmundodelapiscina.com/ckfinder/userfiles/files/benoveteposirofape.pdfIn PDF document text
    • http://pincesorvarshop.hu/editor_up/37146213748.pdfIn PDF document text
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613fb2d8e116f---73999394543.pdfIn PDF document text
    • http://grandp.ru/userfiles/file/57811513768.pdfIn PDF document text
    • http://pc-driver.ru/userfiles/files/64011778639.pdfIn PDF document text
    • http://okna-kurska.ru/page_edit/_samples/userfiles/files/23876565595.pdfIn PDF document text
    • https://yodishit.com/uploads/userfiles/file/64672358364.pdfIn PDF document text
    • http://studioschicchi.eu/userfiles/files/woxovopakotuzudarerola.pdfIn PDF document text
    • http://millecolori.it/images/file/jerevexodozexurekotipo.pdfIn PDF document text
    • http://zerosquareonline.com/file/76413007759.pdfIn PDF document text
    • http://opalbiosciences.com/wp-content/plugins/formcraft/file-upload/server/content/files/161334a050dfd4---xonirapovebeseluvavefelon.pdfIn PDF document text
    • http://yokosohk.com/files/fckfiles/file/13758799632.pdfIn PDF document text
    • http://location-appartement-venise.com/italie_documents/files/31090033680.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/1KS0DP0cxss/uplcv?utm_term=tao+of+jeet+kune+do+pdfPDF 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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000dbb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDBB1 16232 bytes
SHA-256: e06ebeaa2bb94d9bf14337b0794fec2c9c4a66e30291689b6f6234bfe360c8a5
font_01_sfnt_off0000f195.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF195 10372 bytes
SHA-256: 1b7829c1c3c08a5a90b005c60f34c2a51b1c822df1984e4a011fd66776836d9e
font_02_sfnt_off00010935.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10935 21128 bytes
SHA-256: b1e043e36ba5111078a799827cfe696d0d815542b6934824830c990afbf7608f
font_03_sfnt_off00013e9e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13E9E 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1