Malicious PDF — malware analysis report

Static analysis result for SHA-256 d1d13963239f3834…

MALICIOUS

PDF

68.8 KB Created: 2021-09-28 19:52:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-21
MD5: 9b97d43ac2e628e8cb51068b5e736053 SHA-1: 1f090500496dd4976c404f2e49c5c3d0b21187c3 SHA-256: d1d13963239f3834ceb2eb3920a2669df9655cd2f079e2927f7caa1a9034520a
156 Risk Score

Malware Insights

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

The PDF contains numerous embedded URLs, many of which point to compromised CMS upload storage or are part of a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. The document body is heavily obfuscated and does not provide direct user-facing content, but the heuristic firings clearly point to a malicious link farm.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9982

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://f-okinawa.com/img/tmp/files/zawam.pdf In PDF document text
    • https://hv2barrier.com/application/third_party/ckfinder/userfiles/files/femojelixafutepikoges.pdfIn PDF document text
    • https://sananselmo.com/wysiwygfiles/file/legosewi.pdfIn PDF document text
    • https://pharmnet.cz/ckfiles/files/files/xunesinirapejikuvidedoka.pdfIn PDF document text
    • http://kbchina.de/upload/xonidokigurakajova.pdfIn PDF document text
    • http://stin-verdon.fr/assets/Image/files/92879246580.pdfIn PDF document text
    • http://tw-sincere.com/upfiles/editor/files/1734298710.pdfIn PDF document text
    • https://honghow.com/ckfinder/userfiles/files/21971245659.pdfIn PDF document text
    • http://remontnoedelo.ru/wp-content/plugins/formcraft/file-upload/server/content/files/1614639a362a85---79423254764.pdfIn PDF document text
    • http://myxroad.net/upload/userfiles/file///rijuf.pdfIn PDF document text
    • http://belloverde.net/emailer/file/raxosirevediwenejunezakis.pdfIn PDF document text
    • https://baptistfriends.org/media/98962077133.pdfIn PDF document text
    • https://aquaticlandscape.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613be9f5bc0b5---fanozofojarefuvu.pdfIn PDF document text
    • https://v-rshine.com/upload/images/files/43846069165.pdfIn PDF document text
    • http://tichdiem.surecare.vn/uploads/userfiles/file/sewulokaza.pdfIn PDF document text
    • http://i-tos.com/userData/board/file/botos.pdfIn PDF document text
    • http://dekoblickfang.de/userfiles/file/96725404165.pdfIn PDF document text
    • http://www.barbazan-debat.fr/ckfinder/userfiles/files/safadizobituxetokoxudafet.pdfIn PDF document text
    • http://xperion.hu/wp-content/plugins/super-forms/uploads/php/files/9ed7a934ccc576bc6724596af5c32725/falowaxof.pdfIn PDF document text
    • http://csc0311.com/userfiles/file/20210920021926_xd7ruk.pdfIn PDF document text
    • http://teraval.cz/res/file/39408783166.pdfIn PDF document text
    • https://joepromenshealth.com/wp-content/plugins/super-forms/uploads/php/files/ca2b55921c40354d36ece9ebdfcb720a/31487469480.pdfIn PDF document text
    • https://feedproxy.google.com/~r/skout/mBVl/~3/3CAf4wW3hvY/uplcv?utm_term=gta+san+andreas+cheats+ps2+unlimited+healthPDF 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_off0000b01a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB01A 14340 bytes
SHA-256: c0ed226c4ad80ad8fe514874aaa10953debc0a94d7737d51ab3c25b953929ec0
font_01_sfnt_off0000d429.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD429 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off0000ec40.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEC40 10920 bytes
SHA-256: 5ac65879932ec04df9105c709c5534f1bf25c0a2e1854003ed3ea0f4989543b0