Malicious PDF — malware analysis report

Static analysis result for SHA-256 c8140dde23287bdf…

MALICIOUS

PDF

80.0 KB Created: 2021-09-01 15:35:42 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: 462e2e1a23e2d0b88db69122971ce10d SHA-1: c5c1660bb2bfbb07a42aa10bc75f60991dcbf876 SHA-256: c8140dde23287bdf73c14e587c53449c4046726d26ed891d131abc1f92cc2c19
96 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains a link farm pointing to multiple compromised WordPress sites, which in turn host other PDF files. The ML classifier strongly indicates maliciousness, and the structure suggests an attempt to obscure the true destination by chaining through multiple domains. No scripts were extracted, but the overall pattern is consistent with a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9987

Heuristics 5

  • 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://robertmatzuzi-massagetherapist.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/1609f59264d8e5---lakurijebawuradimalek.pdf In PDF document text
    • http://xn--80akij1ajew.xn--p1ai/wp-content/plugins/formcraft/file-upload/server/content/files/160a91b69e8e3c---nuwowodal.pdfIn PDF document text
    • https://coachtourbusrental.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607780a31cfcd---75569486043.pdfIn PDF document text
    • http://iccjsc.com/images/uploads/files/48485550923.pdfIn PDF document text
    • http://sonhanint.com/uploadpic/sun/files/202108140221174000.pdfIn PDF document text
    • https://beautifullifeuk.com/wp-content/plugins/super-forms/uploads/php/files/1ce4e57a918326edb27b580d81406d83/37626452859.pdfIn PDF document text
    • http://jaatkinson.com/userimages/58555664313.pdfIn PDF document text
    • https://www.sevgiliyevideo.net/wp-content/plugins/formcraft/file-upload/server/content/files/160764a6bab649---379446865.pdfIn PDF document text
    • http://suportti.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd08d77ee19---1201691481.pdfIn PDF document text
    • http://accessprecision.com/userfiles/file/86606039251.pdfIn PDF document text
    • https://2greenchicks.com/wp-content/plugins/super-forms/uploads/php/files/bc2c2757098654b5d2e8560d15147e0e/zadedogopofivujedoz.pdfIn PDF document text
    • http://apcmagon.com/userfiles/bejerevuzeguviresit.pdfIn PDF document text
    • http://garderoba.sk/images/_file/fonofifux.pdfIn PDF document text
    • https://isleo.com/i_photos/file/paxixufujaxewopupobasi.pdfIn PDF document text
    • http://www.jimenez-casquet.com/wp-content/plugins/formcraft/file-upload/server/content/files/160dfe960df5eb---lopivo.pdfIn PDF document text
    • http://www.grupohk.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1607d829b54e53---74328619718.pdfIn PDF document text
    • http://originalbau.hu/imagesfiles/gimosof.pdfIn PDF document text
    • https://genesisbehaviorcenter.com/wp-content/plugins/super-forms/uploads/php/files/f3063add2219b8b0bd4e6f192ec1a80e/1771695222.pdfIn PDF document text
    • http://sushinamu.com/uploads/files/98713961447.pdfIn PDF document text
    • http://laptopcuhaiphong.vn/upload/files/1978339176.pdfIn PDF document text
    • https://citytrafik.nu/images/file/makenekobetij.pdfIn PDF document text
    • http://vishwkarmaenterprises.com/webroot/img/userfiles/files/58460125460.pdfIn PDF document text
    • https://samajsutra.com/userfiles/files/renizorotemonofipapi.pdfIn PDF document text
    • https://www.aserspa.net/wp-content/plugins/super-forms/uploads/php/files/t5t84coc32gnu1msvoodldpvm2/95158886636.pdfIn PDF document text
    • https://inverpalmas.com/aym_image/files/borakejilexewidonesunonat.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/3CAf4wW3hvY/uplcv?utm_term=conceptual+in+tagalogPDF 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_off0000d108.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD108 10412 bytes
SHA-256: a27227f30699c7842d0de4d49450b174745fc7955ef0a703fd7148688e58986f
font_01_sfnt_off0000e8ba.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE8BA 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000100cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x100CC 18284 bytes
SHA-256: a44654d7027eee1036dd8c6ffe5502accf079afb653c10f756d50e3292fc416b