Malicious PDF — malware analysis report

Static analysis result for SHA-256 f3cb7bac93bdf576…

MALICIOUS

PDF

70.0 KB Created: 2021-09-24 16:05:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: 31dba53faf919beff1b9e70ea3fa55e6 SHA-1: 71e7841524b9e52015ad7d2f6ae41173341e976b SHA-256: f3cb7bac93bdf576c12bd767441cd07f1bab56413c94e76128cf8b2ce758aa1c
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains numerous links pointing to external websites, many of which are hosted on compromised CMS platforms or disposable domains, indicating a link farm designed to redirect users. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution via these external links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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://inwebjor.ru/uplcv?utm_term=answer+call+with+home+button+android PDF link annotation
    • http://asacnfservices.com/ckfinder/userfiles/files/2362023321.pdfIn PDF document text
    • https://penzion-pod-rozhlednou.cz/img/file/42180485020.pdfIn PDF document text
    • https://bibliotheque.ville.deux-montagnes.qc.ca/ckfinder/userfiles/files/basivebopufebobuzujopa.pdfIn PDF document text
    • https://westcoastmovers.ca/wp-content/plugins/super-forms/uploads/php/files/csoujb5fkrp5tnnldsuk00mb3c/82983349814.pdfIn PDF document text
    • http://stuarteisbrucklaw.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/33831273025.pdfIn PDF document text
    • https://snoman.mb.ca/ckfinder/userfiles/files/nafisewimuzebevawuk.pdfIn PDF document text
    • http://giaydantuongphongkhach.net/images/news/file/97719398225.pdfIn PDF document text
    • https://lorus.rs/files/jamutuvonopogoxuwatoze.pdfIn PDF document text
    • http://tokstar.com/_UploadFile/Images/file/33432700804.pdfIn PDF document text
    • http://fashionflutters.com/ckfinder/userfiles/files/58173032525.pdfIn PDF document text
    • https://serwisnawigacji.pl/userfiles/file/zokororafenemamijiwime.pdfIn PDF document text
    • https://artgallery.devctn.com/ckfinder/userfiles/files/53538622250.pdfIn PDF document text
    • http://ourpreferred.com/userfiles/files/16360848281.pdfIn PDF document text
    • https://beautyyaurient.com/editor_upload/file/20450800255.pdfIn PDF document text
    • http://goodlack.cz/userfiles/file/jobulotugabixasutegu.pdfIn PDF document text
    • https://gamepinleri.net/calisma2/files/uploads/namifo.pdfIn PDF document text
    • http://kalikraft.com/images/file/19298787791.pdfIn PDF document text
    • http://kfnmdg.com/upfolder/e/files/20210902164944.pdfIn PDF document text
    • http://schouteninterieurwerk.nl/wp-content/plugins/formcraft/file-upload/server/content/files/1613d7c3226a5a---nizibami.pdfIn PDF document text
    • https://bxthirteen.wpengine.com/wp-content/plugins/super-forms/uploads/php/files/a3fa64caecebb75be34d48249fad5b45/392733117.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_off0000ae95.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xAE95 16872 bytes
SHA-256: fb75521678f4342a57ff1d4bd6538123c2a6272cbf491ee0fc5ab9a200f7b18f
font_01_sfnt_off0000d975.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD975 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000f18c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF18C 10940 bytes
SHA-256: 51010f99da3281373855ee2d77d484f11389f7769288c7baf1d8ba52c864b2ef