Malicious PDF — malware analysis report

Static analysis result for SHA-256 c91c07cde8994057…

MALICIOUS

PDF

84.8 KB Created: 2021-09-02 05:17:35 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 7883af137b35052ec53fb96eff3db9f3 SHA-1: f289b54d97c709cba9e5912853fc59307b472f1d SHA-256: c91c07cde8994057a66ccee7bcd8a01f2c3a6d7da22864fb061c17e6d06af96e
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It contains numerous external links, many pointing to disposable hosting or compromised CMS upload directories, suggesting a link farm or redirection mechanism. The presence of PDF_SEO_DISPOSABLE_LINK_FARM and PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM heuristics further supports this, indicating the PDF is used to distribute traffic to various external sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9978

Heuristics 6

  • 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 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://nomylo.ru/uplcv?utm_term=aphids+on+brussel+sprouts PDF link annotation
    • http://gocreate.termall.pl/upload/fck/file/8717542547.pdfIn PDF document text
    • https://wfbulgaria.com/uploads/wysiwyg/files/pipotemeko.pdfIn PDF document text
    • http://www.christinemartin.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609c8508388b5---benomidud.pdfIn PDF document text
    • http://mamitobe.ru/files/file/luforajebemapusikinuzur.pdfIn PDF document text
    • https://geneolock.com/locktactyuma/userfiles/file/75832968956.pdfIn PDF document text
    • https://mygo.com/ckfinder/userfiles/files/kilipezenirubuvesowemigez.pdfIn PDF document text
    • http://www.dogwoodagility.nl/ckfinder/userfiles/files/33529472203.pdfIn PDF document text
    • https://la-klamm.org/Files/files/zaxalul.pdfIn PDF document text
    • http://fitviewer.biz/files/file/fidegane.pdfIn PDF document text
    • http://ibshop.gr/uploads/_uploads/files/77612062577.pdfIn PDF document text
    • https://brahmagnanam.org/fck_uploads/file/xaraki.pdfIn PDF document text
    • https://nscs.org/wp-content/plugins/super-forms/uploads/php/files/f6ebd867c400a4f4e405f8285d81cb7d/vovivodedekizu.pdfIn PDF document text
    • https://intelean.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608ede60c646f---kawizew.pdfIn PDF document text
    • https://christembassyromford.org/wp-content/plugins/super-forms/uploads/php/files/e03848ee95276c2e66b0d13d37981694/siwajuwulosilatep.pdfIn PDF document text
    • https://aradovan.com/userfiles/file/kifisutudoravetoxarumuk.pdfIn PDF document text
    • https://www.euroservicemilano.it/wp-content/plugins/formcraft/file-upload/server/content/files/1607beaec0184d---mewowajimaxemiwimok.pdfIn PDF document text
    • http://brilliantsolarpaneling.com/userfiles/file/70960967983.pdfIn PDF document text
    • http://sivam.pl/files/file/28200821115.pdfIn PDF document text
    • https://progin.swiss/ckfinder/userfiles/files/liweviz.pdfIn PDF document text
    • http://placc.info/up_image/36558015801.pdfIn PDF document text
    • http://gulfcoolcontracting.com/uploads/userfiles/file/file/sekinu.pdfIn PDF document text
    • https://agilitynd.com/wp-content/plugins/super-forms/uploads/php/files/07f2d7faed593d28d1a241fd73051114/kulixop.pdfIn PDF document text
    • http://myblindz.com/fck_user_files/file/tukap.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/3ulc90cb5jgl5m12uv3a61ir51/28745181723.pdfIn PDF document text
    • https://expungemyrecordnj.com/wp-content/plugins/formcraft/file-upload/server/content/files/16090d86a5c74a---mudodojefafelobipavaroz.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_off0000e7b0.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7B0 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000ffc7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFFC7 10548 bytes
SHA-256: 0fa7307f481a4e71e7983c7850f8aef65da70cfe03033554e6a0b53989b9bc73
font_02_sfnt_off00011787.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11787 17536 bytes
SHA-256: b33a5aeb9659c927124e50472c32c576bbfd5ac82d38678588d9667f0aae8987