Malicious PDF — malware analysis report

Static analysis result for SHA-256 0b89fd0c7509dce8…

MALICIOUS

PDF

67.5 KB Created: 2021-09-27 20:06:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: f643eac7cc6512c9929e20475cb1a493 SHA-1: 46d800a48cac82932191cc53bc7796d7d66814c2 SHA-256: 0b89fd0c7509dce80986fa3b08365721cc84f6a4e6c651defe3ecfa16851add6
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains numerous embedded URLs, many of which point to compromised websites or are part of a link farm designed to obscure the ultimate destination. The ML classifier and ClamAV detection strongly indicate malicious intent, likely phishing or malware distribution through these links. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, suggesting it's not intended for direct user reading but rather as a container for malicious links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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://www.ojchamber.com/ckfinder/userfiles/files/25412263837.pdf In PDF document text
    • http://huyminhplastic.com/upload/files/12566584190.pdfIn PDF document text
    • https://cokhivietuc.com/img-vietuc/files/34548864254.pdfIn PDF document text
    • https://highendteen.com/userfiles/files/89958357999.pdfIn PDF document text
    • http://ryyw.com/upload/files/2021/09/202109251317082302.pdfIn PDF document text
    • http://eska-lift.ru/userfiles/file/27656904360.pdfIn PDF document text
    • http://dydlhx.com/upfiles/file///16476968712.pdfIn PDF document text
    • https://jensbrode.de/files/file/sowinozekifonokoruxajani.pdfIn PDF document text
    • http://adhdadvisory.com/wp-content/plugins/formcraft/file-upload/server/content/files/16151e71698ca2---zudozuvafofolitupusavaguk.pdfIn PDF document text
    • http://ulv-fogger.es/d/files/38658274403.pdfIn PDF document text
    • http://nuraski.pl/wsg/userfiles/47243705994.pdfIn PDF document text
    • http://hindel-relax.ch/ckfinder/userfiles/files/63548222125.pdfIn PDF document text
    • https://g-ortho.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613000725f2d4---renofevoduvategoxedi.pdfIn PDF document text
    • https://areshin.ru/wp-content/plugins/super-forms/uploads/php/files/980d8a9e545310990cdb8327d8618119/xurusadavikuninogivamo.pdfIn PDF document text
    • http://augustaelectricalwork.com/editorData/file/lebewigut.pdfIn PDF document text
    • http://flightshop.jp/images/blog/file/tegeropafosanetodeg.pdfIn PDF document text
    • https://phatgiaolongan.com/upload/ckupload/files/tujipasejufepefazuvaxibax.pdfIn PDF document text
    • http://studionegro.net/userfiles/files/52737531546.pdfIn PDF document text
    • http://www.hon-ro.hu/userfiles/files/molepulubobekun.pdfIn PDF document text
    • http://reelproductionshd.com/userfiles/file/fojoxijunigiwexege.pdfIn PDF document text
    • http://naturalmis.com/userfiles/file/60047614880.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/LPIa9PGmDLg/uplcv?utm_term=kalaham+tamil+font+for+androidPDF 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_off0000ac91.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAC91 15148 bytes
SHA-256: 2e502986a7fe4e472a402f85a3dbb0f32c7b5fb372006da7c2a966d21b1c1236
font_01_sfnt_off0000d2ac.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD2AC 10312 bytes
SHA-256: 430640999558390b223b90c69e6b7dc610d20d879fbadb87b03392fc6bd1f9eb
font_02_sfnt_off0000e9a1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE9A1 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1