Malicious PDF — malware analysis report

Static analysis result for SHA-256 5f25a4d5e250a975…

MALICIOUS

PDF

84.0 KB Created: 2021-06-28 08:03:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: dfb8652827d28a004ce6147655a90cd4 SHA-1: 4aafb6d485cfb88c290cac42eadb90bff20a2a34 SHA-256: 5f25a4d5e250a975e0b61bf7897d891715fe14a55feb1e96a2d6746813a7414d
156 Risk Score

Malware Insights

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

The PDF contains a large number of links pointing to various websites, many of which are hosted on compromised CMS platforms. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to serve further malicious content. The document body is heavily obfuscated and appears to be non-readable content generated by wkhtmltopdf, providing no direct user-facing lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9972

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://baodinhsolar.com/wp-content/plugins/super-forms/uploads/php/files/qecbl8tmnvdlcu0g12mq6hhmkn/15514402494.pdf
    • https://www.modianodesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16082d5937471a---jojujovuxanatizosonip.pdf
    • https://tecnicadovolante.com/images/file/44512652715.pdf
    • http://www.canadiantreasurer.com/wp-content/plugins/formcraft/file-upload/server/content/files/160d2cb6aadd17---mezalisadututumumiwekelir.pdf
    • http://pmdrecycling.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a4cbe0c8683---nunirezuzubobirosezabi.pdf
    • https://greenturtleproductions.com.au/wp-content/plugins/super-forms/uploads/php/files/e41b6177e1b8fa5c396b263d136a0795/71730050861.pdf
    • https://universal4shipping.net/userfiles/file/66860410187.pdf
    • http://www.eflox.net/wp-content/plugins/formcraft/file-upload/server/content/files/16071ca1dbf01a---kovatuteluwafufip.pdf
    • http://boxethai38.com/upload/file/pexufililurimatifez.pdf
    • http://www.awakohchang.com/image/upload/File/olijasosoronimupowi.pdf
    • https://www.generalutilities.com/wp-content/plugins/formcraft/file-upload/server/content/files/16098441b73b41---64211411845.pdf
    • https://mavismanagement.com/wp-content/plugins/formcraft/file-upload/server/content/files/16094642007657---63192398542.pdf
    • https://supermagnum-bg.com/userfiles/file/zefabetofofonajovegaru.pdf
    • https://www.ayersworthglen.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608e14ec48a2f---64149338532.pdf
    • https://www.parkgest.ch/wp-content/plugins/formcraft/file-upload/server/content/files/160961f02bf145---16104286219.pdf
    • https://www.americanapi.com/wp-content/plugins/formcraft/file-upload/server/content/files/16087a606c9720---buzoroxi.pdf
    • https://summit-christian-academy.org/scauserfiles/files/bogixawetur.pdf
    • https://expresstestingatl.com/wp-content/plugins/super-forms/uploads/php/files/4f749faa70677b3f9e2913442d0723e8/80194513966.pdf
    • https://www.mobytec.com.br/mobytec/wp-content/plugins/formcraft/file-upload/server/content/files/160aae2d4cf549---62718188380.pdf
    • https://ontime-taxi.kg/wp-content/plugins/super-forms/uploads/php/files/052a8eed45bd258028afc8de9dddffb5/95955842730.pdf
    • https://webtraffic.ch/wp-content/plugins/super-forms/uploads/php/files/jjsjv4fk5063g32g1856bh0vqb/rodixanilufidarujogox.pdf
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/GLLx1DTH0VQ/uplcv?utm_term=bacterial+concrete+research+papers
    • 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_off0000e86b.bin
04c6426cc58dc1ebf67af85a25255ce5b8fc28f12869fbf428652b031f20e0e9
pdf-font-stream PDF embedded font (sfnt) at offset 0xE86B 16332 bytes
font_01_sfnt_off000112a6.bin
3b75897c12d2d3c132af420dd8a9940815f30909507ba65ce32a12470d165a64
pdf-font-stream PDF embedded font (sfnt) at offset 0x112A6 10524 bytes
font_02_sfnt_off00012a8d.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0x12A8D 16792 bytes