Malicious PDF — malware analysis report

Static analysis result for SHA-256 a4a88dc16fb6cd5a…

MALICIOUS

PDF

84.0 KB Created: 2021-07-09 01:48:53 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-09-13
MD5: 6a8262a1509fb744246e1a75799ab4e7 SHA-1: 7f431c44b1134f8b790d6e9531058e7dabe3480b SHA-256: a4a88dc16fb6cd5aa9e3171b1a353d9db4105b270fe9faebe3ffb82d463ef6a0
156 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to compromised WordPress sites and other domains, likely intended to lead users to phishing pages or download further malware. The presence of multiple external URIs and link farm heuristics strongly suggests a phishing or malware distribution campaign.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9951

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://mindweave.co.uk/wp-content/plugins/super-forms/uploads/php/files/be3ousrrhngsv92bja7rie100s/56286171690.pdf In PDF document text
    • http://mountmedpharmacy.co.za/wp-content/plugins/formcraft/file-upload/server/content/files/16095fe3c1a40d---loludexije.pdfIn PDF document text
    • https://www.helpforbusymums.com/wp-content/plugins/super-forms/uploads/php/files/e4da81ad14544bc7c922a4ce73414d6b/juguviwina.pdfIn PDF document text
    • http://ahxxzx.com/userfiles/202105/file/bakumowosekezebidijer.pdfIn PDF document text
    • https://gk-termopanel.ru/wp-content/plugins/super-forms/uploads/php/files/3a8a31c2eaaad631e7e308a90c1a193b/mugita.pdfIn PDF document text
    • http://www.peopleoftheheath.com/wp-content/plugins/formcraft/file-upload/server/content/files/160c77b52b1e23---42502805807.pdfIn PDF document text
    • http://beateromer.com/bilder/file/25269446535.pdfIn PDF document text
    • http://jucal.es/images/file/fobuvixolikekibegidum.pdfIn PDF document text
    • http://eco-versute.com/app/webroot/ckfinder/userfiles/files/wewofimesofebagage.pdfIn PDF document text
    • https://noks.cz/wp-content/plugins/formcraft/file-upload/server/content/files/160ada30f3b1b7---lonewulora.pdfIn PDF document text
    • http://copingconversations.com/userfiles/file/82491985304.pdfIn PDF document text
    • https://agrachoff.ru/wp-content/plugins/super-forms/uploads/php/files/69965d35c1f51a635cb1a247ea621826/bawesafagidi.pdfIn PDF document text
    • http://caribsplash.org/wp-content/plugins/formcraft/file-upload/server/content/files/1606d171ce1101---5250144249.pdfIn PDF document text
    • http://zadonskiy.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1607ffddad752e---guresibalamumoz.pdfIn PDF document text
    • https://swimproject.eu/wp-content/plugins/super-forms/uploads/php/files/a6fb73129657d3a19b6110b2d2cacd68/51979588700.pdfIn PDF document text
    • http://duancanhotot.com/upload/files/lajova.pdfIn PDF document text
    • http://haumeaonline.com/userfiles/file/gafefixakigekuruwusik.pdfIn PDF document text
    • https://goldengrowers.com/wp-content/plugins/super-forms/uploads/php/files/26f4b5042ded083dc4da5327f7d1afe3/pisetokusadedejobut.pdfIn PDF document text
    • http://megat.pl/uploaded/fck_files/file/29320913785.pdfIn PDF document text
    • http://geologocarmignani.com/userfiles/files/41266067282.pdfIn PDF document text
    • http://fantasypartyentertainment.com/wp-content/plugins/formcraft/file-upload/server/content/files/16088341f114f7---33461731692.pdfIn PDF document text
    • http://dichvutot99.com/webroot/img/files/7246061713.pdfIn PDF document text
    • http://lookupagency.es/wp-content/plugins/formcraft/file-upload/server/content/files/1608e6c35e718b---rexux.pdfIn PDF document text
    • http://saludocupacionalpso.com/home/wp-content/plugins/formcraft/file-upload/server/content/files/160ac9d930edbd---3900871240.pdfIn PDF document text
    • http://www.risingstars.com.tr/wp-content/plugins/formcraft/file-upload/server/content/files/160992e4ce0617---rasijuvikaroluruje.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/FevRqgeaUVY/uplcv?utm_term=how+to+draw+a+guys+facePDF 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_off0000e7f5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE7F5 16316 bytes
SHA-256: 6c28d9fbc52c131c37abdbd0806e136c4d6410f02320910e7f4d16db3894d315
font_01_sfnt_off0001121b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1121B 10700 bytes
SHA-256: 62ed3b8d13c4b2237c3e837a88eb9c45c60ce9bf8865acef0d8d6355fb3e03af
font_02_sfnt_off00012aad.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12AAD 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1