Malicious PDF — malware analysis report

Static analysis result for SHA-256 cfc7a35190a59b23…

MALICIOUS

PDF

97.3 KB Created: 2021-06-27 20:14:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-07
MD5: 5890a6ed73acd7b520a46681789a1af1 SHA-1: 3baaece62c19cee1cc6bf056206941d73430c19a SHA-256: cfc7a35190a59b2313d5c7dea12e4f43c26feda0e619f44b85c24c8582ef190f
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF contains numerous embedded URLs, many of which point to other PDF files hosted on compromised websites or disposable domains, indicating a link farm designed to redirect users. ClamAV detection and ML classification strongly suggest malicious intent, likely for phishing or malware distribution. No scripts were extracted, but the structure and URL patterns are indicative of a multi-stage attack.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9942

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://krisoc.ru/uplcv?utm_term=two+branches+of+chemistry PDF link annotation
    • https://mimpishiodua.com/contents//files/1499649610.pdfIn PDF document text
    • https://brickbodysupplements.com/newerac2c/userfiles/file/50638124487.pdfIn PDF document text
    • http://markasib.ru/ckfinder/userfiles/files/70375899315.pdfIn PDF document text
    • https://dermo.com/wp-content/plugins/formcraft/file-upload/server/content/files/1608358d915f3c---63423033163.pdfIn PDF document text
    • http://altaprecision.com/userfiles/file/pugiwuzekezekiw.pdfIn PDF document text
    • https://shayangroup.net/wp-content/plugins/super-forms/uploads/php/files/44d20d8393a9763c8780d5904ecf82c7/zipug.pdfIn PDF document text
    • http://worthingtonpark101.com/userimages/tovizopowumu.pdfIn PDF document text
    • http://driver-jazda.pl/upload/file/novusebupexirad.pdfIn PDF document text
    • https://cspdental.com/wp-content/plugins/super-forms/uploads/php/files/71c66b1b9c2cbb4570fecfe4f48c77d1/jalugakifobup.pdfIn PDF document text
    • http://pulsrmedia.com/wp-content/plugins/formcraft/file-upload/server/content/files/160be0af69a3fe---joxudejuvos.pdfIn PDF document text
    • https://weblative.com/wp-content/plugins/super-forms/uploads/php/files/10ikc4gv7lof6blc48f2gcon49/42179501402.pdfIn PDF document text
    • https://thinkglobalcompliance.com/ckfinder/userfiles/files/52463656836.pdfIn PDF document text
    • http://kezmosas.hu/files/file/1133220079.pdfIn PDF document text
    • http://mattstergamer.com/wp-content/plugins/super-forms/uploads/php/files/le89ion29bf1a4qvgih3rcc6c7/pafudifipidomososaromo.pdfIn PDF document text
    • http://bscartridge.com/pic/tawilak.pdfIn PDF document text
    • http://xn----7sbab1bcaqplb0ccyi9d.xn--p1ai/files/file/ridazureborakeroleniza.pdfIn PDF document text
    • http://botanicgardenscafe.com.au/wp-content/plugins/formcraft/file-upload/server/content/files/160c6d265c82af---seziwanifamileg.pdfIn PDF document text
    • http://yokohama-model.com/userfiles/files/3258598523.pdfIn PDF document text
    • http://micronforgacsolo.hu/UserFiles/file/tubibozitasu.pdfIn PDF document text
    • http://www.optionassurance.ca/wp-content/plugins/formcraft/file-upload/server/content/files/1606d3595a8e6a---gabozekafawerenurudedunuk.pdfIn PDF document text
    • https://narimasu-chintai.net/jcfiles/file/41039007180.pdfIn PDF document text
    • http://thamdinhgiadaiquang.com/img/files/14495546763.pdfIn PDF document text
    • http://mirrorgallery.com/wp-content/plugins/formcraft/file-upload/server/content/files/160a9b47c8f81c---jotojitirukewuw.pdfIn PDF document text
    • 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_off000111d4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x111D4 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off000129eb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x129EB 10860 bytes
SHA-256: 7fc6b62bea021f2dfbd69b3d81f6f64e2457f7a31f54ef83ada7f98b1bbdfd3c
font_02_sfnt_off000142ee.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x142EE 19936 bytes
SHA-256: 8163e7600e779abf238cdb63ea110d9e796743ca238761abc20e2c229c563ac6