Malicious PDF — malware analysis report

Static analysis result for SHA-256 631cbdf32e02c3bb…

MALICIOUS

PDF

82.7 KB Created: 2021-10-05 05:45:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-24
MD5: 54a3cf0c3b077aef0ea53c8461edaa6e SHA-1: 00a27d40f8439ea45710511e40fb447a3e4296ab SHA-256: 631cbdf32e02c3bb5de7da8e8abc8a61e5c020a220abb6086e8125b42e23b573
156 Risk Score

Malware Insights

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

The file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the PDF acts as a link farm, directing users to multiple external URLs, some hosted on compromised CMS uploads. These links likely serve as a lure for phishing or to download further malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

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://huntic.ru/uplcv?utm_term=types+of+life+cycle+model PDF link annotation
    • https://hyundainhapkhau.vn/upload/files/38928255039.pdfIn PDF document text
    • http://klenderbio.com/upload/files/darinesik.pdfIn PDF document text
    • http://caacoding.net/wp-content/plugins/formcraft/file-upload/server/content/files/161401d2b8fb93---wusofisozalajiwopeg.pdfIn PDF document text
    • https://fullmagicweekend.com/ckfinder/userfiles/files/vatofixokagutitoguderu.pdfIn PDF document text
    • http://195exim.com/datas/files/fojetiw.pdfIn PDF document text
    • http://robertoantoniz.com/resources/original/file/deritemovebepunogawulo.pdfIn PDF document text
    • http://cpgny.com/userfiles/files/6282651386.pdfIn PDF document text
    • https://mimpidia.com/contents/files/wujebivozepofejasavorib.pdfIn PDF document text
    • http://ewhamd.net/upFiles/ckeditor/files/86244510780.pdfIn PDF document text
    • http://hansungid.com/userfiles/file/46197204622.pdfIn PDF document text
    • https://yaslibakicisi.net/userfiles/file/ragejaxogenogadazomaxobab.pdfIn PDF document text
    • http://www.mvdisposal.com/wp-content/plugins/formcraft/file-upload/server/content/files/161385bbd366a9---19842342887.pdfIn PDF document text
    • http://saltokisport.com/uploads/files/tawilafonojapeberefe.pdfIn PDF document text
    • http://zoscm.zohukum.com/ckfinder/userfiles/files/3925039657.pdfIn PDF document text
    • https://heritagecambodiatravel.com/userfiles/file/69146580667.pdfIn PDF document text
    • https://nutritie-metabolism-sanatate.ro/app/webroot/files/userfiles/files/6480046829.pdfIn PDF document text
    • https://teplitsyoptom.ru/wp-content/plugins/super-forms/uploads/php/files/e7d054c6af6daf4e39add7c3f5a5611a/tezavibufixizemefi.pdfIn PDF document text
    • https://best-turbos.com/wp-content/plugins/super-forms/uploads/php/files/3645de6ff8267decba244f65153cb4f0/61132415902.pdfIn PDF document text
    • http://mko-yug.ru/wp-content/plugins/super-forms/uploads/php/files/15d55e598dc63d131cb16dd586ce23ed/lotokizamapukekogaw.pdfIn PDF document text
    • https://newcar-rental.com/uploads/files/202109080027089029.pdfIn PDF document text
    • http://anabakorea.jp/userfiles/file/jamepi.pdfIn PDF document text
    • https://longhungphat.org/Images_upload/files/72780554623.pdfIn PDF document text
    • http://fli.edu.mn/ckfinder/userfiles/files/magazozerubibamed.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_off0000df7a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDF7A 17956 bytes
SHA-256: 794eec46b03015bb91bc3c3c467738b26f66f6e924f5b0245e24b34834484add
font_01_sfnt_off00010dae.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10DAE 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000125c5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x125C5 10396 bytes
SHA-256: 22af092740e085d64b31f15bcc765e2ecdf06dc73255f34ef02425bd9372ca2c