Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5bb57913ac8ba69…

MALICIOUS

PDF

73.7 KB Created: 2021-09-05 10:31:38 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-11
MD5: 288297e7591b5fa715f794d182410cfe SHA-1: fcaf7b8865b45ea1c0b533ed5cbc5371d59753b4 SHA-256: c5bb57913ac8ba697d0bc918b10d09bb04dc7296b73287adbfa5ba724bef2d45
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by a machine learning classifier and ClamAV, indicating a high likelihood of malicious intent. The document functions as a link farm, with numerous embedded URLs pointing to external sites, some of which are hosted on compromised WordPress installations. While no scripts were explicitly extracted, the nature of the link farm suggests a phishing or credential harvesting attempt, likely delivered via spearphishing attachment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9973

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.web-globus.de/ckfinder/userfiles/files/28375452786.pdf In PDF document text
    • http://akademibt.com/resimler/files/lanune.pdfIn PDF document text
    • https://trucraftsmanship.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c89ca7c05ad---40927785420.pdfIn PDF document text
    • http://ttmplus.com/userfiles/files/66218973109.pdfIn PDF document text
    • http://bora.su/ckfinder/userfiles/files/20869487706.pdfIn PDF document text
    • http://a-kamen.com/userfiles/file/83074351792.pdfIn PDF document text
    • https://jfefood.com/wp-content/plugins/super-forms/uploads/php/files/0a78883bca11210ebff5da11dcf79c9d/65898469783.pdfIn PDF document text
    • https://www.sharpeningfactory.com/wp-content/plugins/formcraft/file-upload/server/content/files/160b541305a899---85351515350.pdfIn PDF document text
    • https://www.tessilgiada.it/wp-content/plugins/formcraft/file-upload/server/content/files/1608fc38cab6e3---nutadokiwajepiti.pdfIn PDF document text
    • https://zerling.eu/nico/images/files/60660542676.pdfIn PDF document text
    • http://choinka4x4.org/cms/files/file/fasavakomugetajegewajabov.pdfIn PDF document text
    • https://sharmtocairo.com/userfiles/files/53614188117.pdfIn PDF document text
    • https://veritiesinstitute.com/wp-content/plugins/super-forms/uploads/php/files/6a8b5f2c63468816e71bca5b161730e4/ruxutoxipaw.pdfIn PDF document text
    • https://immo-cjeanpaul.lu/userfiles/files/17307514749.pdfIn PDF document text
    • http://biomassasia.net/data_ed/userfiles/file/19173551917.pdfIn PDF document text
    • http://businessvaluationapp.com/fck_files/file/ginodi.pdfIn PDF document text
    • http://rc-modeller.se/images/file///5603575598.pdfIn PDF document text
    • http://pileshoppen.dk/userfiles/file/74201122960.pdfIn PDF document text
    • https://acavacecio.it/userfiles/files/kidigovamatexisofemawefo.pdfIn PDF document text
    • http://thetestmag.com/userfiles/files/52288977158.pdfIn PDF document text
    • https://www.c2commercial.com/wp-content/plugins/super-forms/uploads/php/files/e1d56b60772a5121d6bf551787184f25/dijekataresuwezifagona.pdfIn PDF document text
    • https://kimtuong.vn/isc/public/files/fckupload/file/13764060981.pdfIn PDF document text
    • http://wirheiraten.de/images/file/vajazawadefawimoz.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/160c4884b959ae---minaxepe.pdfIn PDF document text
    • https://eminesenlikoglu.org/resimler/files/kawawen.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/A3Ryygt5BCM/uplcv?utm_term=manual+compressor+wayne+wtv+20g%2F250PDF 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_off0000bb10.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBB10 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000d327.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD327 11392 bytes
SHA-256: ebc0fdfdd9db78babe936db234c8886892accd839e2db245249bc080eac36a28
font_02_sfnt_off0000ee45.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEE45 16460 bytes
SHA-256: 5eedc98973f07522df4e40b8e503c219bbef50f59fc0cd8562dfb5d3f60153af