Malicious PDF — malware analysis report

Static analysis result for SHA-256 351a12fcbab69eab…

MALICIOUS

PDF

74.9 KB Created: 2021-09-21 01:45:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-26
MD5: c26408bd52fea2a7d88554eddf938891 SHA-1: 0f15fdae6cc5c7da1995f384b3c23b7e7e4df298 SHA-256: 351a12fcbab69eabf36cb6d758ac3c3874cf39bfcf86f59597d7bc8307744f6f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. Heuristics indicate it functions as a link farm, with many URLs pointing to potentially compromised websites or disposable hosting. The presence of multiple external URIs and the 'PDF_SEO_DISPOSABLE_LINK_FARM' heuristic strongly suggest the document's purpose is to redirect users to malicious sites, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9976

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://brukikostka.pl/uploads/page/file/60425192630.pdf In PDF document text
    • https://mama-light.net/business_school/uploads/file/rizezuburi.pdfIn PDF document text
    • https://nguyenvanhuongloc.vn/app/webroot/files/images/pages/files/98222894383.pdfIn PDF document text
    • http://hamkr.com/userData/board/file/53150400773.pdfIn PDF document text
    • http://genarchi.com/data/temp/file/33085101463.pdfIn PDF document text
    • https://namastehealth.in/wp-content/plugins/super-forms/uploads/php/files/m1r4407fmft5na0tif3ev9rs96/zijazudusaduwevejeni.pdfIn PDF document text
    • https://megashina24.ru/files/files/nagutawoxukad.pdfIn PDF document text
    • https://cissud.it/uploads/ck_editor/files/83623843249.pdfIn PDF document text
    • http://travel-door.com/userfiles/file/linadawipu.pdfIn PDF document text
    • https://mk-promotions.com/ckfinder/userfiles/files/66715628370.pdfIn PDF document text
    • https://www.hotelamoha.it/wp-content/plugins/formcraft/file-upload/server/content/files/16136672bd534b---72318396330.pdfIn PDF document text
    • http://www.pirac.org/wp-content/plugins/super-forms/uploads/php/files/efc18fdcfcb332def0db2027da93dbdb/74046533667.pdfIn PDF document text
    • http://shrlie.com/upload_fck/file/2021-9-1/20210901222527547341.pdfIn PDF document text
    • https://alnahamgroup.com/userfiles/file/widabisidepogolumupuxukuf.pdfIn PDF document text
    • http://eternoohydro.com/d/files/408814863.pdfIn PDF document text
    • http://lexuspolymers.com/assets/ckfinder/userfiles/files/rabixunibefuwikenojebuvo.pdfIn PDF document text
    • http://www.absolutecateringla.com/wp-content/plugins/formcraft/file-upload/server/content/files/16130fdb2b44ea---mujevabevugogelisoja.pdfIn PDF document text
    • https://belitour.ir/basefile/belitourir/files/japujazonebu.pdfIn PDF document text
    • http://okudshava.ru/userfiles/file/29410082327.pdfIn PDF document text
    • http://www.srijonihealinghome.com/fckimages/file/601327893.pdfIn PDF document text
    • http://bulgankhangai.mn/userfiles/files/bidowinozanisaduwobomeban.pdfIn PDF document text
    • https://ccvt.vinaonegroup.net/upload/files/40919993643.pdfIn PDF document text
    • http://15441707.com/data/board/file/20210917160118.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=pokemon+let%27s+go+hacksPDF 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_off0000be61.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBE61 18288 bytes
SHA-256: f5ab1602ac7fec97191c811e6e3db055b4967f368428d30da7843c870035ea69
font_01_sfnt_off0000edb5.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEDB5 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_02_sfnt_off000105cc.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105CC 10612 bytes
SHA-256: f56b2d4e9f4ebfd60e935a0da0180d68aeaed43e2d7bcc64f5484b228c282236