Malicious PDF — malware analysis report

Static analysis result for SHA-256 dc0838b554fba8b8…

MALICIOUS

PDF

81.2 KB Created: 2021-10-05 03:03:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 7d7b324dc382986f02c20bafd377e757 SHA-1: 835a1293f8d7f488d28625608894cfd9c6247f0a SHA-256: dc0838b554fba8b8710828bc1d95e5a2da29e948711c95cccc58d428972429db
146 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded links, many pointing to other PDF files hosted on various domains, suggesting a link farm or redirection mechanism. The 'SE_CALLBACK_LURE' heuristic indicates a potential phishing or tech-support scam context. While no scripts were explicitly extracted, the ML classifier and ClamAV detection strongly suggest malicious intent, likely to deliver a secondary payload or phish credentials.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9975

Heuristics 6

  • 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.
  • Callback phishing phone lure medium SE_CALLBACK_LURE
    Document asks the user to call a phone number in billing, refund, subscription, fraud, or security context — consistent with callback phishing or tech-support scam patterns. Suppressed for legitimate-issuer (IRS/gov/official-form) documents that carry no urgency or charge/dispute escalation.
  • 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://nhakhoasaigonkimcuong.com/uploads/images/files/6944729068.pdf
    • http://insuralead.com/userfiles/file/gekupafefudagid.pdf
    • https://soportedevida.mx/ckfinder/userfiles/files/98635510536.pdf
    • https://riverasphotovideo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1614089bfee4ec---tukevevilejedejepap.pdf
    • https://istanajp.com/contents/files/96673011727.pdf
    • https://francoisdaulte.com/ckfinder/userfiles/files/marodofo.pdf
    • http://fuzoku-kyujin.jp/ckfinder/userfiles/files/45171701479.pdf
    • https://eecpowerindia.com/codelibrary/ckeditor/ckfinder/userfiles/files/lezatotulasugawaporedivuj.pdf
    • https://www.naabelectric.com/userfiles/files/77037922508.pdf
    • http://dragoniresorts.com/userfiles/wujinizulejovup.pdf
    • http://kondicionery-pushkino.ru/upload_picture/file/84777356374.pdf
    • http://acrclubinversores.com/files/galeria/files/81465111960.pdf
    • http://iucecb.com/files/file/javazitid.pdf
    • https://farmacieitaliane.com/documenti/file/84513643492.pdf
    • http://ff-engineering.com/userfiles/files/87970066414.pdf
    • http://obrazyramix.pl/userfiles/file/42582997382.pdf
    • http://avtokit116.ru/!upload/files/16642695872.pdf
    • https://ooobelkom.ru/ckfinder/userfiles/files/17476747470.pdf
    • http://canxetaianhduc.com/images/file/tumidenigiro.pdf
    • https://sidexsideaudio.com/wp-content/plugins/formcraft/file-upload/server/content/files/16155d82b63e8a---23573988340.pdf
    • https://www.tri-or.fr/tri-or/ckfinder/userfilesfiles/11947299876.pdf
    • http://www.smpnuenen.nl/images/files/33104315741.pdf
    • http://leebyenghun.com/new/upload/board/files/45582050464.pdf
    • http://thuexedanang247.com/uploads/image/files/bafexefakewomasaxuroz.pdf
    • http://kino-cosmik.ru/sadm_files/vuxuxujuzajugilajejekopij.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/DOqCt-cVA4I/uplcv?utm_term=rick+and+morty+season+4+part+2+online
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000d13e.bin
0a05d01e0d723ad4ba6eca4aaff25928716f2aa3b105b52dc5df94bdf49448c8
pdf-font-stream PDF embedded font (sfnt) at offset 0xD13E 11124 bytes
font_01_sfnt_off0000eb53.bin
5ca746372d0bbb5a3fc8aa3b590d5a7f03177e8b47765d25f1ddb463897409da
pdf-font-stream PDF embedded font (sfnt) at offset 0xEB53 19504 bytes
font_02_sfnt_off00011ed1.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x11ED1 16792 bytes