Malicious PDF — malware analysis report

Static analysis result for SHA-256 12871b7791904447…

MALICIOUS

PDF

89.8 KB Created: 2021-09-02 11:01:30 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-02
MD5: 5e7b49f3147bf27d3724674f0ae6966c SHA-1: dba4aec1c71ecb0e458f06a5585e4431df53f3d0 SHA-256: 12871b7791904447ea046cee96bf3d5806a8e9da10868585bd71fa62b468db3a
156 Risk Score

Malware Insights

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

This PDF was flagged as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. The heuristics reveal it functions as a link farm, with numerous URLs pointing to compromised CMS uploads and disposable hosting, suggesting an attempt to redirect users to malicious sites. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, further obscuring its true purpose but reinforcing the link farm behavior.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9913

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://www.combatsim.eu/wp-content/plugins/formcraft/file-upload/server/content/files/16075491b1b78d---72588522338.pdf In PDF document text
    • http://inncredel.com/uploads/46343260129.pdfIn PDF document text
    • http://macierz-grodziec.org/files/file/lopire.pdfIn PDF document text
    • https://khangle.vn/uploads/images/files/60573933831.pdfIn PDF document text
    • http://ipublicity.cz/data/file/wukuseririzukiwiludojuko.pdfIn PDF document text
    • http://18554080.com/userfiles/file/kusalufuwulesof.pdfIn PDF document text
    • https://ukmalayalamnews.com/userfiles/file/futedudopijurevub.pdfIn PDF document text
    • http://premiumresourcing.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c7a414e76ee---32999366923.pdfIn PDF document text
    • http://coffee33.ru/archive/file/zezijubaxebawifo.pdfIn PDF document text
    • http://arcadia-fitness.es/userfiles/file/25197304767.pdfIn PDF document text
    • http://www.peplex.it/wp-content/plugins/formcraft/file-upload/server/content/files/16097aa78230b5---30599624286.pdfIn PDF document text
    • https://luxurytravel-show.com/wp-content/plugins/super-forms/uploads/php/files/c4ccf571ac216d267f737562c6c6e61a/33834705557.pdfIn PDF document text
    • http://www.lavalledesign.com/wp-content/plugins/formcraft/file-upload/server/content/files/16080336687ef9---3713378480.pdfIn PDF document text
    • http://domadoma.cz/userfiles/file/57404241451.pdfIn PDF document text
    • https://bangvetthuong.com/luutru/files/6129187713.pdfIn PDF document text
    • http://ketnoikienthuc.com/upload/files/56992319774.pdfIn PDF document text
    • http://vamaconsulting.sk/userfiles/file/jiwewutazedosev.pdfIn PDF document text
    • https://eyetracking.pl/userfiles/file/nojono.pdfIn PDF document text
    • https://eclipsetheaters.com/wp-content/plugins/formcraft/file-upload/server/content/files/16083578824306---93113681983.pdfIn PDF document text
    • http://banphimchuot.com/userfiles/file/6115828508.pdfIn PDF document text
    • https://avayemehr-carpet.ir/data/file/50579534994.pdfIn PDF document text
    • http://hilltopperalumni.com/clients/9/93/936f23dc4abb03f6d4a1aae2c8a32781/File/74724887539.pdfIn PDF document text
    • http://vegasoft.hr/wp-content/plugins/formcraft/file-upload/server/content/files/160bc4b7b61e92---zosovoviwida.pdfIn PDF document text
    • http://lichnyiybrand.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607347263c60e---lumopikos.pdfIn PDF document text
    • http://mq-water.net/upload/41633367531.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/YTWXjIUwRh0/uplcv?utm_term=autocad+structural+detailing+2020+downloadPDF link annotation
    • http://e1pl2.nazwa.pl/busy/fotki/file/kijajonib.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_off0000f5f8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF5F8 18900 bytes
SHA-256: c9d5accf4434b7110f54d5fcee645129a634b701f1b3f3aeff511f281eed797c
font_01_sfnt_off0001278d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1278D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off00013fa4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13FA4 10952 bytes
SHA-256: ed2210e33b9e165e994a9cb5bec0e571ab48bd77a02dc03074acfc3be51918d9