Malicious PDF — malware analysis report

Static analysis result for SHA-256 1a9c3195b855fcd4…

MALICIOUS

PDF

80.9 KB Created: 2021-09-10 13:20:36 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 5c5499843f867736b0aee33102e48900 SHA-1: bf13d3dcd7d18ebe0ee4a0655315be75481a2f36 SHA-256: 1a9c3195b855fcd480bef891c872e58a3ac44dff40d57d3c5b6a6dddbae76e93
156 Risk Score

Malware Insights

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

The PDF file was flagged by ClamAV as Pdf.Phishing.Trojan and by an ML classifier as malicious. It contains numerous embedded URLs that form a link farm, with several pointing to compromised WordPress sites. The primary purpose appears to be redirecting users to external resources, likely for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9960

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://krisoc.ru/uplcv?utm_term=apk+lexis+audio+editor PDF link annotation
    • https://web-sila.ru/wp-content/plugins/super-forms/uploads/php/files/6fc31d8188c14e07e3350248946d50b7/fuxuwasekobefuxoz.pdfIn PDF document text
    • http://builderall.info/userfiles/file/gogovosodugosemedas.pdfIn PDF document text
    • https://aftaplan.com/works/peepsparty/html/upload_files/file/63639352356.pdfIn PDF document text
    • https://stradatextiles.com/upload/ckfinder/files/14695894950.pdfIn PDF document text
    • https://dichvuhappyhouse.com/upload/files/62245675735.pdfIn PDF document text
    • https://pikhospital.com/ck_uploads/uploads/files/febaxexovetejujuvubufukiw.pdfIn PDF document text
    • https://toyotaautobody.com/ckfinder/userfiles/files/nubikajibosi.pdfIn PDF document text
    • http://myconnect-thailand.com/image/upload/File/59222884499.pdfIn PDF document text
    • http://www.leesii.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135db65ddf4f---89014958035.pdfIn PDF document text
    • http://shahgrp.com/uploads/kajavujexepapudegaled.pdfIn PDF document text
    • https://lwim-ouargla.dz/ar/files/jujofatawasevijis.pdfIn PDF document text
    • https://global-product.org/CKEdit/upload/files/76553456063.pdfIn PDF document text
    • http://master-vin.ru/files/file/61743673860.pdfIn PDF document text
    • http://technestudio.eu/userfiles/files/65103984315.pdfIn PDF document text
    • http://wbbray.com/wp-content/plugins/formcraft/file-upload/server/content/files/16135f7645d833---11890391570.pdfIn PDF document text
    • https://ddriu.hu/wp-content/plugins/super-forms/uploads/php/files/428ede99aaf961179abec03660180dba/96366097334.pdfIn PDF document text
    • https://ceral.pl/ceral/pliki/file/79706457246.pdfIn PDF document text
    • http://assotechne.eu/userfiles/files/didexasuwavema.pdfIn PDF document text
    • https://mimpishio1bet.com/contents/files/24730475762.pdfIn PDF document text
    • http://www.1atlanticfunding.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b1ae409295---31261862156.pdfIn PDF document text
    • http://lynxauto.ru/userfiles/file/gujupufuguvisujenofoso.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 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c79b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC79B 21088 bytes
SHA-256: d10e3fac9cba456d799afa99e736fe8fbcb76b0136a7a41e98817a3908276956
font_01_sfnt_off0000fdaf.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFDAF 10556 bytes
SHA-256: 05d4058dd4a5c7d4ca163c9e5c79f15e865d531a3483c4b9967b6bab5f228dd0
font_02_sfnt_off000115f3.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115F3 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_03_sfnt_off00012e00.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12E00 1680 bytes
SHA-256: 6c08887b596ecb472c5a0482df8c2f828d83fc5b5d16111ed0caa1fced1b35dc