Malicious PDF — malware analysis report

Static analysis result for SHA-256 c72312af8decd797…

MALICIOUS

PDF

81.8 KB Created: 2021-10-07 21:59:54 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: c36506b2b9f25c1a38742eb419da8bba SHA-1: 5196a587a3e223b9a111bf55e55ba993ebad8a02 SHA-256: c72312af8decd797892fc8472e2aa72adfe39d5d60024e7ebbc87296401d4eb3
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The sample was flagged by ClamAV as Pdf.Phishing.Trojan and an ML classifier with high confidence. It contains numerous embedded URLs, many of which point to compromised CMS upload storage or disposable hosting, indicating a link farm designed to redirect users to malicious content. The presence of these links and the overall heuristic findings strongly suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9981

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
  • 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.
  • 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=plan+section+and+elevation PDF link annotation
    • https://helicopterleasingservices.com/userfiles/files/35869679987.pdfIn PDF document text
    • http://kapsalonindex.nl/images/uploads/fipidareri.pdfIn PDF document text
    • https://oykufestivali.com/ckfinder/userfiles/files/xefubukekoveturibatuwupu.pdfIn PDF document text
    • https://icoachyou.biz/images/ckeditor/files/72374129668.pdfIn PDF document text
    • http://kubkao-kubpla.com/userfiles/files/97212662803.pdfIn PDF document text
    • http://seritour.com/rsm/files/rozigadokogafati.pdfIn PDF document text
    • http://designbyjoseph.com/uploads/File/polepe.pdfIn PDF document text
    • http://ztkammer.at/uploads/file/26953857621.pdfIn PDF document text
    • https://www.lire-les-notes.com/ckfinder/userfiles/files/jedawekubuxiki.pdfIn PDF document text
    • https://sanruouvang.net/images/uploaded/file/monalerumefevexi.pdfIn PDF document text
    • http://www.farmaciavictoriayjmleon.com/userfiles/files/47749195913.pdfIn PDF document text
    • https://bizdrive.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1/1615cae8d8559c---taxanegosixavisopid.pdfIn PDF document text
    • https://mavibusiness.it/file/60658523942.pdfIn PDF document text
    • http://tea-ra.com/user_data/upload/save_image/files/3061129787.pdfIn PDF document text
    • https://www.yoursurveysurveyors.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/16153a86d3a5ea---25986287121.pdfIn PDF document text
    • http://nanobubblevietnam.com/uploads/userfiles/file/74812023451.pdfIn PDF document text
    • http://xn--h1acbpobggs.xn--p1ai/data/files/5249553689.pdfIn PDF document text
    • https://www.inter-tube.co.uk/wp-content/plugins/super-forms/uploads/php/files/f6b1f1aa350aa169398408f7c59831b2/divowirizamiludebip.pdfIn PDF document text
    • https://rayvoltbike.tw/geektic/files/bewovujomevebamidozi.pdfIn PDF document text
    • https://worldcastlive.com/userfiles/file/60775447969.pdfIn PDF document text
    • http://www.sunaryem.com.tr/wp-content/plugins/super-forms/uploads/php/files/cgsu0lbu3vs31h0hnrto0p1rv0/lovevazidozixaduwig.pdfIn PDF document text
    • http://german-ex.com/images/blog/file/49554265099.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_off0000dd64.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDD64 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f576.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF576 17632 bytes
SHA-256: 5d55af66a2faa97a1fc12dcff2362af4041d3ef77e4680773173174ed5c91d6b
font_02_sfnt_off00012221.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12221 10332 bytes
SHA-256: c67cf9aa5f2d6f35ad2855808eec5aeeef8b29186a6827d8ba80ed7735eadd57