Malicious PDF — malware analysis report

Static analysis result for SHA-256 b894311b357b709b…

MALICIOUS

PDF

82.2 KB Created: 2021-09-18 17:33:40 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-27
MD5: ac17496b912acbf3bdda5f9355df9e82 SHA-1: 903cae0f03baae36f34962d4f6758d4ee2043542 SHA-256: b894311b357b709bd55cb1af342f9ecac6fab456cd1f47ab86aca45160c7a770
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The PDF file was identified as malicious by ML classifiers and ClamAV, specifically flagged as a phishing trojan. Heuristics indicate it functions as a link farm, directing users to multiple external URLs, some hosted on compromised CMS platforms. While no scripts were explicitly extracted, the PDF structure and URL patterns suggest an attempt to redirect users to malicious content, likely for phishing or malware delivery.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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 http://norilskgu.ru/userfiles/file/motubuwigaxoxiwi.pdf In PDF document text
    • https://ottopianos.nl/files/fuxebikigo.pdfIn PDF document text
    • https://gabconstruction.com/ckfinder/userfiles/files/37326880996.pdfIn PDF document text
    • http://flairpens.ru/uploads/file/xemofabarawipowijakapavi.pdfIn PDF document text
    • http://yjccnc.com/upload/files/vodapixapojuv.pdfIn PDF document text
    • http://medicare-darmstadt.de/bilder/UserImages/file/29382100795.pdfIn PDF document text
    • http://dalnoboy.net/data/filestorage/upload/files/74661257442.pdfIn PDF document text
    • http://ekopaczka.pl/imgbrama/files/torudevufuwos.pdfIn PDF document text
    • http://gabinetpro.gabinetpro.pl/kosmetyczka/krakow/files/kudijamorowuvitowugub.pdfIn PDF document text
    • http://tuvanluatdanang.com/upload/ck/files/94951405563.pdfIn PDF document text
    • http://riverla.vn/uploads/userfiles/file/4037974597.pdfIn PDF document text
    • http://wmc21.com/ckupload/files/werelofirezirekus.pdfIn PDF document text
    • https://www.entornopublicitario.com/wp-content/plugins/super-forms/uploads/php/files/8be67ba9a8617e6a6d2490c8b52fc35a/ralavedaf.pdfIn PDF document text
    • http://kdsonline.org/userfiles/file/tefibijiretuzikufobujaga.pdfIn PDF document text
    • http://yuanda-boiler.com/d/files/vitinigeponitipez.pdfIn PDF document text
    • http://om-ar.com/userfiles/file/famibot.pdfIn PDF document text
    • http://automozg.by/upload/editor/files/kirevonumizubitagilegekom.pdfIn PDF document text
    • http://xinyuemu.net/assets/202109/files/20210917032024637830.pdfIn PDF document text
    • https://www.diktu.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613c96efb9cbf---vijadozivegesudozevegozad.pdfIn PDF document text
    • https://indianhairtransplant.com/ckfinder/userfiles/files/guxepupepikuvijafogiz.pdfIn PDF document text
    • https://f1com.ge/wp-content/plugins/super-forms/uploads/php/files/448862f5baa371084567391793ab4efd/6771498994.pdfIn PDF document text
    • https://feedproxy.google.com/~r/1eyvgo/aqOO/~3/BkSY9tpko7c/uplcv?utm_term=indian+songs+ringtones+for+androidPDF 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_off0000de99.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDE99 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f6ab.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6AB 17356 bytes
SHA-256: 2e374c6a969a01e812e4e5439490231480a8d0149bd2eeab545f26e2283ab246
font_02_sfnt_off000123cd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x123CD 10436 bytes
SHA-256: cbcf2225bff98cef5a745ea27b69746f63809db1916d39dc34b5a90563034cbb