Malicious PDF — malware analysis report

Static analysis result for SHA-256 99ff4ebb185cbf10…

MALICIOUS

PDF

77.1 KB Created: 2021-07-28 09:56:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-29
MD5: 3141f91ec779d6c792d506ea2ffdc227 SHA-1: 1a5737bec04cd29071da1b22f8cda656ad5603f3 SHA-256: 99ff4ebb185cbf100f0cee9d6749a7be67b2e56db200db6d61a570f8d99a838c
156 Risk Score

Malware Insights

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

The sample was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. Heuristics indicate the PDF acts as a link farm, directing users to multiple external websites, some of which are hosted on compromised CMS uploads. The presence of numerous links on disposable hosting further supports a malicious purpose, likely for phishing or malware distribution.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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 http://etnorom.hu/pictures/52406990431.pdf In PDF document text
    • https://chicagoportablexray.com/wp-content/plugins/formcraft/file-upload/server/content/files/160fe25ef4c7dd---71406193400.pdfIn PDF document text
    • http://starlightcelebre.org/clients/4/43/43e9139217482d7666ce300faf566241/File/gebugusegisetajexas.pdfIn PDF document text
    • http://tasarimak.com/ckfinder/userfiles/files/lenomunilivilup.pdfIn PDF document text
    • https://jodhpurtravels.com/nbloom/fckuploads/file/97696801453.pdfIn PDF document text
    • https://www.potterycommercials.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1607ee27f1b60e---bijevavagibufezafujun.pdfIn PDF document text
    • http://tilestone-pools.com/i/File/kegaditixuj.pdfIn PDF document text
    • http://www.iycadana.org/wp-content/plugins/super-forms/uploads/php/files/lj81pn28e5vtomhrasr110ut84/75434869017.pdfIn PDF document text
    • https://simondaulte.com/ckfinder/userfiles/files/95681008186.pdfIn PDF document text
    • https://shared401k.com/wp-content/plugins/super-forms/uploads/php/files/7860bc5c76837696235acb66129f1acd/xibazinapigunage.pdfIn PDF document text
    • http://cerrutistudio.eu/userfiles/files/19161141364.pdfIn PDF document text
    • http://cl-metalparts.com/d/files/jodasefe.pdfIn PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160c002552bd63---femadafupasalarulusujaked.pdfIn PDF document text
    • http://www.roosprommenschenckelfoundation.nl/ckfinder/files/files/vusatinekizuwijedifum.pdfIn PDF document text
    • http://www.deadclan.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1607e2e7d9edea---bomugo.pdfIn PDF document text
    • http://sowa-architekci.pl/userfiles/files/berexozewetazuro.pdfIn PDF document text
    • https://atolab.it/wp-content/plugins/super-forms/uploads/php/files/e768d3870f59f012507ab2e6eb6161b8/36729630520.pdfIn PDF document text
    • http://eurogeographyjournal.eu/admin/fckfiles/file/67314092628.pdfIn PDF document text
    • http://chonburi33.com/userfiles/file/38523649900.pdfIn PDF document text
    • http://noithatdangcap.vn/app/webroot/uploads/files/kekixo.pdfIn PDF document text
    • http://lambanghieuquangcaogiare.net/vietkiendo/upload/file/zomopadip.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/1608d2f0324ecf---8011622453.pdfIn PDF document text
    • http://www.tiande-global.com/ckfinder/userfiles/files/fisuzepefiwax.pdfIn PDF document text
    • http://villaturri.com/wp-content/plugins/formcraft/file-upload/server/content/files/1609edbba34af0---81001060888.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BvfzZFkJO3s/uplcv?utm_term=calcular+la+masa+molecular+de+fe2%28so4%293PDF link annotation
    • 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_off0000c550.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC550 17940 bytes
SHA-256: aba0edd2467e68ec8f0fb7c3059613cb579439796a1d3c3a5ef22731c4646b79
font_01_sfnt_off0000f313.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF313 11000 bytes
SHA-256: c90463755efb466664fbac44e5fcc9fc7e4d9a6a636f8f394f73b327a41e7092
font_02_sfnt_off00010ce7.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CE7 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1