Malicious PDF — malware analysis report

Static analysis result for SHA-256 21936b3b4fa9532e…

MALICIOUS

PDF

84.2 KB Created: 2021-09-07 14:36:26 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 273ab0669ce30cfd8f1394ea60895771 SHA-1: 4f28244fc1a09ebfff5e0c64a7b79ca8a7f34fca SHA-256: 21936b3b4fa9532e35ce7f779044b9542f83a9c12145478ccc83716a214c320b
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

The PDF contains a large number of external links, many of which point to compromised WordPress upload directories or other potentially malicious sites. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or to serve further malware. No scripts were extracted, but the link farm structure itself is the primary attack vector.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9860

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://aksaxena.com/bpms/includes/fckeditor_uploads/userfiles/file/4112527737.pdf In PDF document text
    • http://esistore.be/userfiles/file/75367758348.pdfIn PDF document text
    • https://jordan.si/dokumenti/file/97857694701.pdfIn PDF document text
    • http://bubblesoflove.net/wp-content/plugins/formcraft/file-upload/server/content/files/160c8ecd3ca90e---3802973195.pdfIn PDF document text
    • http://www.skup.it/wp-content/plugins/formcraft/file-upload/server/content/files/16079cac00d221---12377528840.pdfIn PDF document text
    • http://sciencevier.com/wp-content/plugins/formcraft/file-upload/server/content/files/1607a4fcf57cdc---89377503351.pdfIn PDF document text
    • http://omonetach.pl/foto/ilustracje/file/mowigeganiguv.pdfIn PDF document text
    • http://interel-rus.ru/test/sites/default/files/file/fikidolobotig.pdfIn PDF document text
    • http://nissanotogovap.com/uploads/images/files/43029941882.pdfIn PDF document text
    • http://tincorner.vn/uploads/files/faxekaboxura.pdfIn PDF document text
    • http://alrabbancapital.com/file/files/jefobumagisudar.pdfIn PDF document text
    • https://www.carlosfunes.es/wp-content/plugins/formcraft/file-upload/server/content/files/160882f0ccea9b---85133984891.pdfIn PDF document text
    • http://pytextiles.com/userfiles/file/95731970179.pdfIn PDF document text
    • http://veronicanealhome.com/wp-content/plugins/formcraft/file-upload/server/content/files/2/1607b32379a912---mewutotatimipi.pdfIn PDF document text
    • http://vasamo.org/pds/userfiles/files/33061180593.pdfIn PDF document text
    • https://bettenbaehren.de/wp-content/plugins/formcraft/file-upload/server/content/files/160a125ca16b55---xejomokonubodenupu.pdfIn PDF document text
    • http://www.ncstarim.com.tr/wp-content/plugins/super-forms/uploads/php/files/r16p7o74dlqi8kfglalqd6rs04/lejibugezavodiw.pdfIn PDF document text
    • http://fuerst-architects.com/uploads/file/26711290267.pdfIn PDF document text
    • http://xn--90ad5ackt1d.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/b24f510af915855c531b4bc2e269bac8/bojotelofuzotaboravazi.pdfIn PDF document text
    • http://epicridesnepal.com/files/79639225134.pdfIn PDF document text
    • http://extreamtuning.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1608cb946926f2---93492952281.pdfIn PDF document text
    • https://www.sixteengrams.com/wp-content/plugins/super-forms/uploads/php/files/7op2e3tcb6u3okp8ll9rkd7psr/dumisemumesimotejigixu.pdfIn PDF document text
    • http://www.qookspot.kitchen/wp-content/plugins/formcraft/file-upload/server/content/files/1607a4881e68d7---5938242979.pdfIn PDF document text
    • http://www.musicmaestrodiscos.co.uk/wp-content/plugins/formcraft/file-upload/server/content/files/160855b4b5a004---55023784691.pdfIn PDF document text
    • http://agiteam.org/clients/b/b0/b0c4817036ef1cb73596cc935f3fa86d/File/tozokixozufajuna.pdfIn PDF document text
    • http://dorp.pl/userfiles/files/48985678819.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/BvfzZFkJO3s/uplcv?utm_term=fractura+del+5to+metatarsiano+pdfPDF 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_off0000e2de.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE2DE 18376 bytes
SHA-256: 174c9545ca5f604af2789ea649342dc74cce046a0f93e7bbc14a4bbdd699818d
font_01_sfnt_off00011163.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11163 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0001297a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1297A 10992 bytes
SHA-256: 58c964c60c7e3ef108b0bae2ae71c0bdd72898e018617420914cba5a2a041b56