Malicious PDF — malware analysis report

Static analysis result for SHA-256 5b6a4c215d1ec85a…

MALICIOUS

PDF

68.8 KB Created: 2021-09-22 21:00:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: f78f7bada0a70a8646e95d4e8cb4c383 SHA-1: 128cb4e0a36f3b79dbd14d5f2a84fe4ba42c6083 SHA-256: 5b6a4c215d1ec85a473c755ed81da641ff9d8758c8a86ec9b4a65f56d1b8a749
156 Risk Score

Malware Insights

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

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads. The presence of 'utm_term=android+malware+download' in one URL suggests a potential lure for mobile malware, although no specific script or exploit was directly observed.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://kaplaitalia.it/userfiles/files/49513945113.pdf In PDF document text
    • https://arrayamed.com/userfiles/file/91375093866.pdfIn PDF document text
    • https://sunpower.lv/ckfinder/userfiles/files/pivazegijijepe.pdfIn PDF document text
    • https://brawlcall.jordanadams.com/ckfinder/userfiles/files/62923829664.pdfIn PDF document text
    • http://grupposcorcia.it/userfiles/files/35128781075.pdfIn PDF document text
    • http://www.supair-lux.hu/ckfinder/userfiles/files/23874693948.pdfIn PDF document text
    • https://tierrettung-in-katalonien.org/ckfinder/userfiles/files/vadukoguzalaredajulo.pdfIn PDF document text
    • http://kondicionery-noginsk.ru/upload_picture/file/kuwuj.pdfIn PDF document text
    • http://lncxjzxxw.com/upload_fck/file/2021-9-5/20210905173847740764.pdfIn PDF document text
    • https://fsbulletsandbrass.com/userfiles/files/sexusebapuxegiwomijid.pdfIn PDF document text
    • http://rootbeadmill.com/upload_fck/file/2021-9-20/20210920235355650153.pdfIn PDF document text
    • https://casadko.fr/userfiles/file/71945604921.pdfIn PDF document text
    • https://dukeofmarshall.com/ckfinder/userfiles/files/58027087510.pdfIn PDF document text
    • http://hueide.com/upload/files/vogaxuruzuta.pdfIn PDF document text
    • http://studiolaviano.it/userfiles/files/wifimadigolodijenowegavar.pdfIn PDF document text
    • https://drivingschoolofnorthtexas.com/wp-content/plugins/formcraft/file-upload/server/content/files/161413de3bd376---vosogoxugirodame.pdfIn PDF document text
    • http://kondicionery-shodnya.ru/upload_picture/file/90417759442.pdfIn PDF document text
    • https://www.gml.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612fa919a1776---74679323206.pdfIn PDF document text
    • http://jd6618.com/jd6618/file/2021-9/file/LwpCms2021_09_16_01_14_01_6184.pdfIn PDF document text
    • http://ahknchem.com/upload/files/xurizisifemadanolewunetus.pdfIn PDF document text
    • https://sirikulsteel.com/wp-content/plugins/formcraft/file-upload/server/content/files/161493b22b3f78---69942009079.pdfIn PDF document text
    • http://violetstudio.in/userfiles/file/koborexuwuz.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/PmAiG5ZyT-k/uplcv?utm_term=android+malware+downloadPDF 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_off0000b221.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB221 14628 bytes
SHA-256: aba00fe35b4f66adcd76e4650efb0f438d0db0f81d69cc8c5f024c915ff15601
font_01_sfnt_off0000d702.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD702 10208 bytes
SHA-256: 3802e7dc3cf6cd1dcfc2e8359f33b11680dc0640a0cb270eaf51616af9bc5522
font_02_sfnt_off0000eddc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDDC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1