Malicious PDF — malware analysis report

Static analysis result for SHA-256 de668b392c7c5103…

MALICIOUS

PDF

70.2 KB Created: 2021-09-22 11:26:18 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-16
MD5: 88f32fa43055918724b106ec057bfd33 SHA-1: ce009a4971543c56507837c18707fcebb2ba0d21 SHA-256: de668b392c7c51034d061e8e07ca9ab6b42db6e7023ccbb2804815b1a3125eda
166 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains multiple heuristic firings indicating malicious intent, including a high-severity PDF_RANDOM_URL_LINK and ML_NYX_PDF_MALICIOUS. The document body is heavily obfuscated, but the presence of numerous external URIs, many pointing to potentially disposable domains, suggests a phishing or malware distribution attempt. The primary attack vector appears to be a deceptive link designed to trick users into downloading a secondary malicious PDF.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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 to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not a PDF parser vulnerability.
  • 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://garglob.ru/uplcv?utm_term=springer+handbook+of+robotics+pdf PDF link annotation
    • http://www.waetsukai.jp/system/ckfinder/userfiles/files/mimewutu.pdfIn PDF document text
    • https://superiorservicesandsolutionsfl.com/nbloom/fckuploads/file/kupugabilo.pdfIn PDF document text
    • http://klm-co.ru/foto/ck/files/nutupopovel.pdfIn PDF document text
    • https://tnmkor.com/FileData/ckfinder/files/20210921_C794131DC595AA79.pdfIn PDF document text
    • https://jakspravnenapsa.cz/userfiles/file/84766459090.pdfIn PDF document text
    • https://www.crossfitparamaribo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614114b4b12a4---34511109000.pdfIn PDF document text
    • http://kleinschaden.expert/userfiles/file/8357040146.pdfIn PDF document text
    • https://giorgiosantinelli.it/file/75755982566.pdfIn PDF document text
    • https://www.pactforfamilies.org/ckfinder/userfiles/files/sukidipulavotisulinetuv.pdfIn PDF document text
    • http://sofia-es.tokyo/yamituki-n/uploads/files/febeviwuwekerolumanazoru.pdfIn PDF document text
    • http://wedooverseas.com/userfiles/file/24660992733.pdfIn PDF document text
    • http://thrifty-uy.com/files/others/baroxemesiniwagewenim.pdfIn PDF document text
    • https://anaksemut.com/contents/files/kosava.pdfIn PDF document text
    • http://cosonhuath.com/hinhanh_fckeditor/file/guxef.pdfIn PDF document text
    • http://agriturismoilnoceto.com/userfiles/files/wajun.pdfIn PDF document text
    • http://matrixpaint.com/ckfinder/userfiles/files/60379399817.pdfIn PDF document text
    • http://clingac.com/d/files/59002242493.pdfIn PDF document text
    • http://neo-net.info/giganet/files/file/72557063926.pdfIn PDF document text
    • http://drkoopman.nl/cmsimages/file/vejikirurimutuma.pdfIn PDF document text
    • http://humanitool.ru/userfiles/file/kerozumegoxenuxanejexi.pdfIn PDF document text
    • http://www.klimavill.com/data/editorfile/fawezekuvakaku.pdfIn PDF document text
    • http://ilsogno-bomboniere.com/userfiles/files/37349736022.pdfIn PDF document text
    • http://inannamsao.com/uploads/files/dimunuremoxu.pdfIn PDF document text
    • https://www.spitalmoldovanoua.ro/ckfinder/userfiles/files/72305562273.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_off0000b31f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB31F 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000cb36.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCB36 11160 bytes
SHA-256: 590a1d0f7c82cc8adac9b7dd03a6ccdeee889225c53486d0c8f9208b5d3509be
font_02_sfnt_off0000e4c2.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE4C2 15052 bytes
SHA-256: 108181387c144324620ec6d324fe9eec61f3ac904a371a0236b9781f4ee97e2c