Malicious PDF — malware analysis report

Static analysis result for SHA-256 87396aef103cb0d8…

MALICIOUS

PDF

83.1 KB Created: 2021-07-15 14:15:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-14
MD5: 992753127369e52b73b1e9c5c10c96f1 SHA-1: 6025bdc702e17677236c0add8fb6ca567243f983 SHA-256: 87396aef103cb0d831a010ccc8cd5657c1e0365ff1db3cc5e515404f32d14d56
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF document was flagged by ClamAV as a phishing trojan and a machine learning classifier indicated a high probability of maliciousness. Several heuristics identified the PDF as a link farm hosted on compromised WordPress sites, with numerous distinct hosts and disposable hosting. While no scripts were explicitly extracted, the presence of embedded URLs and the nature of the link farm suggest an attempt to redirect users to malicious content, likely as part of a phishing campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

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://queuemanagementsystems.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bfe1e66614b---82853041138.pdf In PDF document text
    • https://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/160b21964d39d9---xejudisupuxul.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/e78f9314ad5b09f3da344ceacc5c99c6/14499846341.pdfIn PDF document text
    • https://lexconsulting.ro/webroot/files/media/tobejuduzaf.pdfIn PDF document text
    • http://gtshotel.it/images/file/95076587154.pdfIn PDF document text
    • http://klingende-zeder.de/wp-content/plugins/formcraft/file-upload/server/content/files/16087fcd4bf0d9---samaso.pdfIn PDF document text
    • http://dok-vo.ru/userfiles/file/60024786556.pdfIn PDF document text
    • http://tulsacentral1963.com/clients/3/39/398188050227c7f1c8b3045a0a865105/File/73701510180.pdfIn PDF document text
    • http://bettaletroom.com/file_media/file_image/file/segorulupopamolasitupor.pdfIn PDF document text
    • https://dongytueduc.com/wp-content/plugins/super-forms/uploads/php/files/32ce2nigteh74f3e8930vp5pl9/muligerutisatufeliko.pdfIn PDF document text
    • https://www.ideakliniksisli.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b887ea95ced---bawisojazofopo.pdfIn PDF document text
    • https://widepolymers.com/userfiles/file/situdevo.pdfIn PDF document text
    • http://abpaluso.com/upload/file/dowesizexu.pdfIn PDF document text
    • http://lavera.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608d0e25862f8---42192432293.pdfIn PDF document text
    • http://thecreditcrisis.net/clients/73966/File/nanuvodagegevi.pdfIn PDF document text
    • https://bmw-zona.ru/uploads/file/darazoxikup.pdfIn PDF document text
    • https://smarttactic.ro/wp-content/plugins/formcraft/file-upload/server/content/files/160b00b0facc33---mizalumamidoxo.pdfIn PDF document text
    • http://bruisedreedfoundation.org/clients/4/4d/4d9d7eec3bf3a09fa0457ace138f6a4e/File/58140654940.pdfIn PDF document text
    • https://edusfera.pl/upload/file/koxilojowaxi.pdfIn PDF document text
    • http://blissrenewbeauty.com/newerac2c/userfiles/file/jatiluzasigun.pdfIn PDF document text
    • http://summithighschool1958.com/clients/71652/File/80049209158.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160aaf8f1cb735---pumarivuwojif.pdfIn PDF document text
    • https://123kozijnofferte.nl/wp-content/plugins/super-forms/uploads/php/files/i36e3g479cs95v9abcgmkbukb7/jukitafagakulorakitolapi.pdfIn PDF document text
    • http://www.theflightfest.com/wp-content/plugins/formcraft/file-upload/server/content/files/16093f49b03e4a---wewodokikebuwenokirido.pdfIn PDF document text
    • http://smartmedicaleg.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607c86c15291c---71977617393.pdfIn PDF document text
    • https://feedproxy.google.com/~r/Uplcv/~3/fzgW7-mxBc0/uplcv?utm_term=because+it%27s+too+cold+for+you+here+lyricsPDF 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_off0000e02d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE02D 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f844.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF844 10772 bytes
SHA-256: d4ff5ed021a7a4b0513b4eed6f6884a1355b5fd72c726e081fb957098d835f02
font_02_sfnt_off00011140.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11140 17332 bytes
SHA-256: 9a7fcc9450869264dbee61e13b5c824661976a8b76027d4700959fe888ce1670