Malicious PDF — malware analysis report

Static analysis result for SHA-256 a57a53f1cbc0bf27…

MALICIOUS

PDF

69.8 KB Created: 2021-09-28 03:55:52 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: 9e038e5e0395ae71698421b949868edb SHA-1: 4b4dc8463cda8f644651dae141e0596c4d59f45f SHA-256: a57a53f1cbc0bf275e1d04fb5b56255d394038e003dacbf46db4218599a6b613
126 Risk Score

Malware Insights

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

The PDF file was flagged by multiple heuristics, including a medium-severity rule indicating it's a link farm on disposable hosting. The ML classifier and ClamAV also identified it as malicious. The numerous embedded URLs suggest a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9956

Heuristics 5

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://synerhu.ru/uplcv?utm_term=professor+snape+potions+class PDF link annotation
    • https://tktravelkorea.com/FileData/ckfinder/files/20210909_21A7DDDEC77F8FA3.pdfIn PDF document text
    • https://anbuadidravidarmatrimony.com/ckfinder/userfiles/files/gujebagujetuvitowe.pdfIn PDF document text
    • http://stitesattorney.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/gupoxozomas.pdfIn PDF document text
    • https://dansobentre.net/uploads/file/36692307404.pdfIn PDF document text
    • https://bestofbucerias.com/upload/file/38328973832.pdfIn PDF document text
    • https://aathichudi.org/userfiles/file/kiburi.pdfIn PDF document text
    • https://bharatceramics.in/ckfinder/userfiles/files/suzuzewazigika.pdfIn PDF document text
    • http://xingzhongjing.com/userfiles/file/20210915202838_1109438379.pdfIn PDF document text
    • http://market-oborudovanie.ru/upload/file/bijuvixatukepade.pdfIn PDF document text
    • https://www.allterra.group/wp-content/plugins/super-forms/uploads/php/files/2d5ead401e2647463bfb41f4c43958d5/88785672537.pdfIn PDF document text
    • http://www.mueblesgamez.com/ckfinder/userfiles/files/dikifizoxemux.pdfIn PDF document text
    • http://madveras.com/ckfinder/userfiles/files/31528191854.pdfIn PDF document text
    • http://alrehabourhome.com/userfiles/files/jikesetopoge.pdfIn PDF document text
    • http://zl369.net/userfiles/file/lixugozufuwili.pdfIn PDF document text
    • https://lifesmart.ro/ckfinder/userfiles/files/durokigibonutir.pdfIn PDF document text
    • https://akamercedes.com/images/uploads/files/ruguxumovajexurodesibozo.pdfIn PDF document text
    • https://thietbixanh.net/uploads/files/bofituvogimajiloxetoni.pdfIn PDF document text
    • http://www.biharikft.hu/bihari-admin/ckfinder/userfiles/files/peburefujedetikeximu.pdfIn PDF document text
    • http://nesemlak.com/test/images/uploads/files/27820798789.pdfIn PDF document text
    • http://salamino.pl/userfiles/file/14843088531.pdfIn PDF document text
    • http://edilcfcostruzioni.com/userfiles/files/sukabozowedevesazu.pdfIn PDF document text
    • http://donghozibistore.com/luutru/files/62175088137.pdfIn PDF document text
    • http://hieuchuan.com/upload/files/36987140635.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_off0000aed0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAED0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000c6e7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC6E7 10472 bytes
SHA-256: 3597df07e061de14a15f73d705b7ff60606d54fc64249d0fbd0f02be860a039b
font_02_sfnt_off0000ded8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDED8 16560 bytes
SHA-256: 7d7b9b9d0ea469512f163aad48b8da8ed38783a108425e80654a63d8fbadccf5