Malicious PDF — malware analysis report

Static analysis result for SHA-256 a93c346c191cba86…

MALICIOUS

PDF

73.9 KB Created: 2021-09-17 05:18:11 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-23
MD5: 5a66351d682a0bd2c6f549021297ebf0 SHA-1: ef7567bd2db0a197be112ddb873bcaeec5c562a2 SHA-256: a93c346c191cba86d0566ca055a9c75500e205022d71a2ad5a4d2d1347c13bec
156 Risk Score

Malware Insights

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

The PDF file was flagged by a machine learning classifier and ClamAV as malicious, specifically as a phishing trojan. It contains numerous embedded URLs that point to various domains, many of which appear to be compromised WordPress sites or disposable hosting, suggesting a link farm designed to redirect users to malicious content. The presence of these URLs and the heuristic firings strongly indicate a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9840

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 https://chcial.ru/uplcv?utm_term=lamour+hack+apk PDF link annotation
    • http://wieswioska.pl/userfiles/file/78098167731.pdfIn PDF document text
    • http://uteambio.com/upload/files/xonitononazaxulo.pdfIn PDF document text
    • http://husplaza.hu/editor_up/721095836.pdfIn PDF document text
    • http://ahzycw.com/upload_fck/file/2021-9-4/20210904145837583642.pdfIn PDF document text
    • https://bliznacite.com/files/75484523396.pdfIn PDF document text
    • https://dom4m.by/userfiles/files/guxupukox.pdfIn PDF document text
    • https://gesema.com/UserFiles/file/daregibuxo.pdfIn PDF document text
    • https://magnettoptan.com/upload/ckfinder/files/42468046473.pdfIn PDF document text
    • http://twfindia.in/userfiles/files/xupelaxa.pdfIn PDF document text
    • http://specimport.by/files/files/tadapixidenefanexaz.pdfIn PDF document text
    • http://sooam.com/files/fckeditor/file/1408256696133e5250f1ba.pdfIn PDF document text
    • http://xn--80ackbssfuieecff0e8c.xn--p1ai/wp-content/plugins/super-forms/uploads/php/files/dltd6qhksp7ahsg6o487p9fil2/80560360557.pdfIn PDF document text
    • https://pierrelemagicien.com/userfiles/file/8235725112.pdfIn PDF document text
    • http://agppi99.pretty-match.com/upload/files/gitezopo.pdfIn PDF document text
    • http://julieesteban.com/wp-content/plugins/formcraft/file-upload/server/content/files/161386e8111750---32786600684.pdfIn PDF document text
    • https://fo-prefectures.com/pages/files/77173829358.pdfIn PDF document text
    • http://www.hebrewforreadingcomprehension.com/content/53871513525.pdfIn PDF document text
    • http://bimbrlata.cz/UserFiles/File/97453050980.pdfIn PDF document text
    • https://galerie-louise.be/userfiles/files/61688979239.pdfIn PDF document text
    • http://chocolatycakes.com/wp-content/plugins/formcraft/file-upload/server/content/files/1612fc0a6c0d6a---masagewivururatagi.pdfIn PDF document text
    • http://pzhjintai.com/upload/files/14713982888.pdfIn PDF document text
    • http://tandartsindex.nl/images/uploads/buxekefuvavuvadibor.pdfIn PDF document text
    • https://melnikhouse.com/userfiles/file/jojabopigamuvureditad.pdfIn PDF document text
    • http://vigova.vn/Images_upload/files/22077839352.pdfIn PDF document text
    • http://eunlocker.com/Images/Editor/file/10563389623.pdfIn PDF document text
    • http://aisne.proximeo.com/ckfinder/userfiles/files/vufajedofelukoxale.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_off0000bf6f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xBF6F 17204 bytes
SHA-256: b91da5da5a45c869f622aa55da8638c4725c0c8239649cdc6d61979731f459ad
font_01_sfnt_off0000eb9c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEB9C 10148 bytes
SHA-256: b5bb5d633ff49b793ff0a9b4e1aee84be988ee944a451b5c72771891fbdb9b5a
font_02_sfnt_off00010246.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10246 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1