Malicious PDF — malware analysis report

Static analysis result for SHA-256 e58fcaa88651d39b…

MALICIOUS

PDF

81.4 KB Created: 2021-09-23 03:36:21 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f42e74b3f855fdb84ea8297cbf05d149 SHA-1: 7fdc03fbcc131e91a7131d0b0f2b063d4819a21b SHA-256: e58fcaa88651d39be0bee30fbd4f69018a5ad2bdaf387db1c3ec89ceeb1a7634
156 Risk Score

Malware Insights

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

This PDF file was flagged by multiple heuristics and a machine learning classifier as malicious, with ClamAV identifying it as a phishing trojan. It contains numerous embedded URLs, many pointing to compromised CMS upload storage or disposable hosting, suggesting a link farm designed to redirect users to malicious sites. The document body is heavily obfuscated and unreadable, indicating an attempt to hide its true purpose.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9968

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 https://queure.ru/uplcv?utm_term=smart+launcher+theme PDF link annotation
    • http://musorcentrum.hu/files/article/file/luwoni.pdfIn PDF document text
    • https://www.hit-education.com/wp-content/plugins/super-forms/uploads/php/files/fui3pcmqsb5n8sqctgkd8fa8u5/wekokitafepefebuzivagexa.pdfIn PDF document text
    • http://makaifruits.com/wp-content/plugins/formcraft/file-upload/server/content/files/16141387650119---23959415476.pdfIn PDF document text
    • http://rs-entp.com/upload/file/36773660898.pdfIn PDF document text
    • http://crosswaysrecruitment.com/userfiles/file/70644108085.pdfIn PDF document text
    • https://eghamatkade.com/basefile/eghamatkadecom/files/62185307526.pdfIn PDF document text
    • http://ratchee.com/ckfinder/userfiles/files/60329101291.pdfIn PDF document text
    • http://chapaconoticias.com/assets/ckfinder/core/connector/php/uploads/files/namugixodetisenu.pdfIn PDF document text
    • https://schreinerheusi.de/wp-content/plugins/formcraft/file-upload/server/content/files/1613fe992e9013---36470291727.pdfIn PDF document text
    • https://altsovmun.ru/userfiles/file/21927060194.pdfIn PDF document text
    • http://michalpavlicek.com/uploaded/file/zezibifegerezozugawokup.pdfIn PDF document text
    • http://qualityfirstservices.pro/testingsites/advantage_aviation/assets/media/file/92336476742.pdfIn PDF document text
    • https://cairparavel.ro/app/webroot/files/userfiles/files/xurimo.pdfIn PDF document text
    • https://taechoclub.com/FileData/ckfinder/files/20210911_E2B265E2B1D18BFF.pdfIn PDF document text
    • http://studiosaletta.it/userfiles/files/84491669757.pdfIn PDF document text
    • http://serdceprirody.ru/userfiles/file/tetevizajefurosabe.pdfIn PDF document text
    • http://tranhdaquydep.vn/upload/files/29049672899.pdfIn PDF document text
    • https://vanvoorst.info/uploaded/file/panib.pdfIn PDF document text
    • http://yuanhebiotech.com/upload/files/37094345564.pdfIn PDF document text
    • https://linker.tw/files/14657355068.pdfIn PDF document text
    • https://thepetrichortouch.com/wp-content/plugins/super-forms/uploads/php/files/qad0n4iv25h56tk20h4nvdajpc/bewigi.pdfIn PDF document text
    • http://bikaji.zohukum.com/ckfinder/userfiles/files/xoxeneridafomuse.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_off0000db3a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB3A 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f351.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF351 10288 bytes
SHA-256: 4c5462b3d8acbc81b9acee372b98ac3d486c8f2372187021a37ddf9f0f745b78
font_02_sfnt_off00010a47.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10A47 18088 bytes
SHA-256: 251003d3a0b435fdbdfef1b0f061da266b85b712c622f929ffad818e6e15e0d2