Malicious PDF — malware analysis report

Static analysis result for SHA-256 b53a4473218a5456…

MALICIOUS

PDF

84.1 KB Created: 2021-09-02 16:06:41 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-05
MD5: c765a089c43375cd2354a5d906e20c19 SHA-1: a5985854a162f152fd0dcfcd0fb4774d51600831 SHA-256: b53a4473218a5456762db8f955f3e8a0c0f5efd53e281a477d6c5b13798d791d
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was flagged by ML classifiers and ClamAV as malicious, specifically as a phishing trojan. It contains numerous links pointing to potentially compromised websites and disposable hosting, suggesting an attempt to redirect users to malicious content. The document body is heavily obfuscated and appears to be generated by wkhtmltopdf, indicating it's not intended for human readability but rather as a container for malicious links.

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 https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/1612050289b09c---suluxutozupikapuvukofin.pdf In PDF document text
    • http://arebiatours.com/uploads/files/dulinexupuvopitizozoj.pdfIn PDF document text
    • https://travelselection.us/wp-content/plugins/formcraft/file-upload/server/content/files/16082530b2e22e---sojamawomesodomosixu.pdfIn PDF document text
    • https://www.azembay.com/wp-content/plugins/super-forms/uploads/php/files/edh61gfonmcadqa1op0iqcdk4q/30974436160.pdfIn PDF document text
    • http://24cvety.ru/upload/files/56399808928.pdfIn PDF document text
    • http://purofirstli.net/userfiles/file/25065192194.pdfIn PDF document text
    • https://bataretak.com/img/files/file/towoniwitegimixal.pdfIn PDF document text
    • https://skyzoan.com/cake/beta/userfiles/file/sofepuni.pdfIn PDF document text
    • http://eotp.info/sites/default/files/fck/file/11401955670.pdfIn PDF document text
    • http://hellnocancershow.com/wp-content/plugins/formcraft/file-upload/server/content/files/1611d0921e4cfa---38533601021.pdfIn PDF document text
    • https://alfa-clining.ru/wp-content/plugins/super-forms/uploads/php/files/af6e2bdd26c4ab5aa03bc30941044b6d/82199362257.pdfIn PDF document text
    • https://hyundainhapkhau.vn/upload/files/xuwube.pdfIn PDF document text
    • http://haki.vn/uploads/files/43984803303.pdfIn PDF document text
    • http://akicgiyim.com/userfiles/file/84272029068.pdfIn PDF document text
    • http://drvision.org/wp-content/plugins/formcraft/file-upload/server/content/files/160b3615f5f2c8---29535279452.pdfIn PDF document text
    • http://travisreunion.com/clients/1/1d/1d9c560ef9ee6310b862f4c9d288d7bd/File/17653502509.pdfIn PDF document text
    • http://mtegl.wsystem.sk/userfiles/files/xemobugizuravigi.pdfIn PDF document text
    • http://slowjamsundays.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607739741daa4---wilisuzifenitajobuva.pdfIn PDF document text
    • http://www.hollyskauaicondo.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b4dca81125a---45668444231.pdfIn PDF document text
    • https://www.reparaciondebomba.com.ar/wp-content/plugins/super-forms/uploads/php/files/h5qnig9tteh816cq3pg4da0c95/26044254225.pdfIn PDF document text
    • http://www.1000ena.com/wp-content/plugins/formcraft/file-upload/server/content/files/160bd9f2993609---38708106719.pdfIn PDF document text
    • http://fornacedelia.it/userfiles/files/fuzegux.pdfIn PDF document text
    • http://www.jesuseslaroca.org/wp-content/plugins/formcraft/file-upload/server/content/files/1609e2ab41a8ce---87344101485.pdfIn PDF document text
    • https://tiklatakip.com/calisma2/files/uploads/48287670482.pdfIn PDF document text
    • http://avtoarka.ru/wp-content/plugins/super-forms/uploads/php/files/da1e4f03c5489dbd7f560986a471aeaa/51723501399.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/PmAiG5ZyT-k/uplcv?utm_term=convert+pdf+to+jpg+freeware+portablePDF 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_off0000e418.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE418 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000fc2a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFC2A 17516 bytes
SHA-256: e82c48c4b19298741bb69d6d5a5af8a369e23f2ee62735cc3901863316e8166f
font_02_sfnt_off000129e1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129E1 10868 bytes
SHA-256: 78c31a0fbbaa923f246ef71d68523110c45838a8b3ae2c5c255cd4bfc9f7f261