Malicious PDF — malware analysis report

Static analysis result for SHA-256 c57793bd89e71c02…

MALICIOUS

PDF

85.5 KB Created: 2021-09-09 22:20:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 5ce7b5a8947897c776764741c7ebbca4 SHA-1: 834982ac1d165b74618d9c7d326101c411bcf39e SHA-256: c57793bd89e71c029bf1bfd5f9263d45351dea7153ffa3f3b0c6c4f475cda5fd
176 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, with numerous embedded URLs pointing to various domains, some of which are hosted on compromised WordPress sites. The presence of 'utm_term' parameters suggests a phishing or spam campaign aimed at directing users to potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

Heuristics 7

  • 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.
  • QR-code redirect lure medium SE_QR_LURE
    Document instructs the user to scan a QR code with a phone — consistent with QR phishing, but also common in legitimate documents
  • 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://coretry.ru/uplcv?utm_term=android+11+latest+version PDF link annotation
    • http://richmore.kr/uploadfile/fckeditor/file/39091690378.pdfIn PDF document text
    • http://www.abcklima.hu/data/editorfile/pitud.pdfIn PDF document text
    • http://iamsoldierfit.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612f47364edcf---vixabulujiwalunijoj.pdfIn PDF document text
    • http://www.birapart.com/wp-content/plugins/formcraft/file-upload/server/content/files/161375936429b3---tulowak.pdfIn PDF document text
    • http://biaikatolikus.hu/files/file/26584884869.pdfIn PDF document text
    • http://gpkoaee.ru/ckfinder/userfiles/files/gegok.pdfIn PDF document text
    • http://isitekmuhendislik.com/userfiles/file/ruxurebusal.pdfIn PDF document text
    • https://leavereview.com/customerinterview/ckfinder/userfiles/files/27308703698.pdfIn PDF document text
    • http://xn--38-mlcqjbufcz6h.xn--p1ai/userfiles/file/97723158172.pdfIn PDF document text
    • http://qhzs88.com/admin/fckeditor_upfiles/file/2021090801454080554.pdfIn PDF document text
    • http://sinching.com/uploadpic/files/202109050508554654.pdfIn PDF document text
    • https://dcicz.org/userfiles/file/29982264291.pdfIn PDF document text
    • http://www.ih-consultant.com/ckfinder/userfiles/files/pasodizigupiletara.pdfIn PDF document text
    • https://www.businesswatchguardingservices.co.uk/wp-content/plugins/super-forms/uploads/php/files/b405rprehkf02l152jpmqk1ds5/jusuxas.pdfIn PDF document text
    • http://brette-animation.com/userfiles/file/5646860143.pdfIn PDF document text
    • http://erex.hu/upload/file/wanuralajotilekoje.pdfIn PDF document text
    • http://mtkshop.com/images/uploads/file/lemagisegukotedikefori.pdfIn PDF document text
    • http://pietroquatriniarchitetto.eu/userfiles/files/wilik.pdfIn PDF document text
    • https://duhocblueocean.vn/ckfinder/userfiles/files/litizapasigam.pdfIn PDF document text
    • https://hinaweb.com/upload/file/zaxulikamarevexem.pdfIn PDF document text
    • https://handinhand-daycare.com/ckfinder/userfiles/files/82672889864.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_off0000ea98.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEA98 10340 bytes
SHA-256: 5a9278c0ea9d4167d1ef6d8d4e0d873f336ad5da3932425daf5f04d615ebe55d
font_01_sfnt_off0001021d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1021D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00011a2f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11A2F 17536 bytes
SHA-256: 2391d8a1bea794fc49140eaa76523d0accad04a8009d7b965f25b5fec9606aba