Malicious PDF — malware analysis report

Static analysis result for SHA-256 83dbd79309581331…

MALICIOUS

PDF

81.8 KB Created: 2021-09-10 18:50:02 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c68846017865e8603f83535665b7ef25 SHA-1: 335277786df27ddfcb37066ba93d966d5050f0c3 SHA-256: 83dbd793095813319e91087864d8e6ec7f06e9f47849b829df99cd08b54767a8
174 Risk Score

Malware Insights

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

The sample is identified as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The PDF contains numerous links to external files, many of which are hosted on potentially disposable domains, suggesting a link farm or downloader. The presence of a 'download button' heuristic further supports the attack pattern of luring users to download a payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9977

Heuristics 7

  • 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.
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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 http://xy-interior.com/uploads/files/202109090632198532.pdf In PDF document text
    • http://www.tobywells.org/media/fckdir/file/venuzekasomezelolepegi.pdfIn PDF document text
    • http://chonburi33.com/userfiles/file/61422152530.pdfIn PDF document text
    • https://alhasooncorp.com/Files/files/wazuzipimulatexogorugebor.pdfIn PDF document text
    • http://ilsungwarehouse.com/userData/ebizro_board/file/domogo.pdfIn PDF document text
    • https://at2-turbo-j3t.com/contents/files/kexemexuxamagelalavob.pdfIn PDF document text
    • https://deltaguvenlik.net/userfiles/file/fulelazugawujamok.pdfIn PDF document text
    • https://smartstone.ca/userfiles/files/letikel.pdfIn PDF document text
    • https://dimensioninteractive.com/WYSIWYGImage/file/81275622330.pdfIn PDF document text
    • https://cantellodetersiviprofessionali.it/uploads/file/48549972020.pdfIn PDF document text
    • https://ph789.com/pinhsuan/files/file/39677931395.pdfIn PDF document text
    • https://floresdeserrezuela.com/aym_image/files/4583534335.pdfIn PDF document text
    • http://ccadl.com/files/20210904203731.pdfIn PDF document text
    • http://oawebserver.com/piceditor/file/50344574573.pdfIn PDF document text
    • http://goldnumber.info/userfiles/file/godowekawamuzofigiz.pdfIn PDF document text
    • http://gallery4walls.com/upload/editer/file/51863707988.pdfIn PDF document text
    • https://voyageaventurenepal.com/upload/files/xomajosozilelufolaxif.pdfIn PDF document text
    • https://quangcaowebsitecomvn.xemlaco.com/uploads/files/90717246433.pdfIn PDF document text
    • http://julianina.dk/upload/file/botefojanobejesiw.pdfIn PDF document text
    • http://www.agrosystem.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/1613537e04bfae---joxubumebirejexofexazosa.pdfIn PDF document text
    • https://tigapilar.com/upload/files/vegilifiwotilu.pdfIn PDF document text
    • https://gabinetpro.pl/kosmetyczka/krakow/files/92507107798.pdfIn PDF document text
    • https://phnews.ro/files/file/80176122435.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/DOqCt-cVA4I/uplcv?utm_term=chrome+lite+apk+downloadPDF 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_off0000da61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDA61 17840 bytes
SHA-256: 027bfc6124abdbbec30d10ab2ef3a654570d0a8eec69ec6c8ac575c86b4b3b80
font_01_sfnt_off00010922.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10922 10696 bytes
SHA-256: 9ad0e2b1e3ae71e3a657260d10af3ab30c871aa3dfa8fb57d373b748f03bf2c6
font_02_sfnt_off00012188.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12188 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1