Malicious PDF — malware analysis report

Static analysis result for SHA-256 4c15e17bebb243ba…

MALICIOUS

PDF

86.0 KB Created: 2021-06-28 20:19:04 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 522315a5bb3ddcbe515a5215d6307908 SHA-1: f7bf545f84570b3b6f6e2ee165fa71eb0bd3feec SHA-256: 4c15e17bebb243ba6cfd2237443e4ef4a7be71b7ab6d355134e331730063e037
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The sample is a PDF file flagged by ClamAV as a phishing trojan and by an ML classifier. It contains numerous embedded URLs, many of which point to compromised WordPress sites and are structured as a link farm. While no scripts were directly extracted, the PDF structure and embedded links suggest a phishing or malware distribution attempt, likely delivered as a spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

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://biomassasia.net/data_ed/userfiles/file/29984615651.pdf
    • http://www.kreasoft.mx/wp-content/plugins/formcraft/file-upload/server/content/files/1609c286a9e027---tetudaza.pdf
    • http://www.radiopopiatej.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098fada8227b---59730802193.pdf
    • http://www.linkkorea.co.kr/wp-content/plugins/formcraft/file-upload/server/content/files/160a0bdd78d21e---dadosugoz.pdf
    • https://renault-service.com/userfiles/gibimumexozafimogipomote.pdf
    • http://amfmeg.org/wp-content/plugins/formcraft/file-upload/server/content/files/160d23e16e7853---1997344059.pdf
    • https://p99.tw/pro_pic/files/55751919524.pdf
    • https://www.audioclinica.pt/wp-content/plugins/super-forms/uploads/php/files/jda7d7tept5ldvpbvav84lv20f/woxenofopawofulu.pdf
    • http://finsura-lifedirect.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160b305ac6622a---sodikidawuwijivimevirov.pdf
    • https://uaqbakery.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607b7bb649b4a---65370031818.pdf
    • http://lawcab.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1609ee3752857b---9645795017.pdf
    • https://estidevelopers.com/wp-content/plugins/super-forms/uploads/php/files/087ebffe2dd2a8a70b171c0f77463f99/86192755502.pdf
    • http://mfcwestenkwartier.nl/beta/userfiles/file/5814341770.pdf
    • https://festivalecolo.ca/wp-content/plugins/formcraft/file-upload/server/content/files/160b79bd69adf5---fozafaloxefixidosotagut.pdf
    • https://c4ir.ae/wp-content/plugins/super-forms/uploads/php/files/4on3qrrms5fksnf7fqgu7mubf0/kisusomokuranimapepofus.pdf
    • http://www.etoiles-recrutement.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b3078a01ce9---54061123928.pdf
    • http://www.majoriscambio.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/160c90d2777e91---1803330514.pdf
    • http://bizwd.com/wp-content/plugins/formcraft/file-upload/server/content/files/16072d4f91e1fa---98355477743.pdf
    • http://www.gunyagder.org.tr/wp-content/plugins/super-forms/uploads/php/files/93qej5effmd234j660t25jgm04/xozosonapefupevosilu.pdf
    • https://militarynetwork.ca/wp-content/plugins/formcraft/file-upload/server/content/files/16071aa16ec34a---35672810079.pdf
    • https://ringid.vn/ckfinder/userfiles/files/20563804075.pdf
    • https://gofropack.com/wp-content/plugins/super-forms/uploads/php/files/e4928e12f2eb55f03c88008850a3566a/28972340205.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/YTWXjIUwRh0/uplcv?utm_term=definition+of+existent
    • 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_off0000ed9e.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xED9E 16792 bytes
font_01_sfnt_off000105b0.bin
930fb0e727fad456131850a9ceb73294868600364fc7887d9c523e25e97ea521
pdf-font-stream PDF embedded font (sfnt) at offset 0x105B0 18100 bytes
font_02_sfnt_off000134ba.bin
4fe98d38f3be129491653159dc65e9bec64d97c183a85e9c4ff38c60648c4c96
pdf-font-stream PDF embedded font (sfnt) at offset 0x134BA 10000 bytes