Malicious PDF — malware analysis report

Static analysis result for SHA-256 a6d9155d3fb43b3f…

MALICIOUS

PDF

73.2 KB Created: 2021-09-13 21:00:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 864785ee14e2810f95575b127b37c291 SHA-1: 7485ca5340f0ca3e530b8e938fd735e8a923501c SHA-256: a6d9155d3fb43b3f4b1dbbcd0961f582b07b07cbdc9d63aaf55b6cfddaa127ef
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. The heuristics reveal it contains a link farm pointing to compromised websites and disposable hosting, likely serving as a lure for users to download further malicious content. The presence of a visual download button further supports a phishing or scamming attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9910

Heuristics 8

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • Malformed active-content stream length medium PDF_MALFORMED_EXPLOIT_STREAM_LENGTH
    A PDF stream that carries active/exploit-looking content has a declared /Length that does not match the recovered stream body. Malformed stream boundaries and length mismatches are common parser-evasion/supporting evidence around Reader exploit streams.
  • 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.
  • 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 https://crysiq.ru/uplcv?utm_term=apk+download+by+link PDF link annotation
    • http://buyyoutubelikes.com/ci/userfiles/files/61078833237.pdfIn PDF document text
    • http://abwnickersonplaza.com/uploads/files/74694548438.pdfIn PDF document text
    • http://dywin.com/uploadfile/files/78981792565.pdfIn PDF document text
    • https://ises.ca/phpsites/vertical_living/uploads/file/36845880654.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/16137b6cfefc61---36599854155.pdfIn PDF document text
    • https://nhaccugiare24h.com/uploads/userfiles/file/pexuxuzaperujolosaxaf.pdfIn PDF document text
    • http://mrybalko.ru/files/ximenovoxeruw.pdfIn PDF document text
    • http://bursaceyizgelinlik.com/images_upload/files/76854218869.pdfIn PDF document text
    • https://net-mex.hu/ckfinder/userfiles/files/30655854526.pdfIn PDF document text
    • http://cargo3030.ru/wp-content/plugins/formcraft/file-upload/server/content/files/161353fc8d5a25---bakulosub.pdfIn PDF document text
    • http://adhunikjewellers.com/ckfinder/userfiles/files/lefipowujamaf.pdfIn PDF document text
    • https://dananeye.com/uploads/files/202109082048389946.pdfIn PDF document text
    • http://nitexprofi.cz/userfiles/file/fuwox.pdfIn PDF document text
    • http://www.satunatc.ac.th/ckfinder/userfiles/files/renigatazigis.pdfIn PDF document text
    • https://cvzona.lt/resources/img/files/topipezotufe.pdfIn PDF document text
    • https://rdw-wolf.de/backend/ckfinder/userfiles/files/biriduburuzimebujupakud.pdfIn PDF document text
    • http://rosesrealtyhomes.com/userfiles/files/kaxuposipefudoriwilakux.pdfIn PDF document text
    • http://medwin.kr/userData/board/file/59376174852.pdfIn PDF document text
    • https://mudateconmigo.cl/wp-content/plugins/super-forms/uploads/php/files/912a527b01b89640a5b2c8aef682a4a0/wikejipitegemofek.pdfIn PDF document text
    • http://snieznik.pl/userfiles/file/79612799302.pdfIn PDF document text
    • http://farmaciafici.com/userfiles/files/saworibinotejokap.pdfIn PDF document text
    • https://xedulichhaiphong.vn/images/news/files/xixunigugetapi.pdfIn PDF document text
    • http://a899.net/userfiles/file/suzuvaz.pdfIn PDF document text
    • http://fisioterapiasuzzara.it/userfiles/files/81520217031.pdfIn PDF document text
    • http://ytlcases.com/userfiles/file/12231095713.pdfIn PDF document text
    • https://xn--espaoldetalca-lkb.cl/var/www/html/upload/file/17736392204.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_off0000bc9a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBC9A 10300 bytes
SHA-256: 6eb9079a1ac983208e3bd1476b0365fb17e84adb69ea4896798500cdbfdd2ed6
font_01_sfnt_off0000d3a9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD3A9 17016 bytes
SHA-256: b89e4dc0ce947e07fb28b12dfca96e8b4b907fd7a1a8608e2542a0c0af1c86fd
font_02_sfnt_off0000fef5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFEF5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1