Malicious PDF — malware analysis report

Static analysis result for SHA-256 90ab2544bba1c98a…

MALICIOUS

PDF

69.6 KB Created: 2021-10-01 13:07:10 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-11-25
MD5: 286d4fa3cd9cdf7f449355980a67f604 SHA-1: 4e9a247c4f3887ad872825899e33c733a2351ee5 SHA-256: 90ab2544bba1c98ac147a564213403a79922b8ca62ec99eaed2aa1788facf4e1
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected as malicious by ML classifiers and ClamAV, indicating a high likelihood of malicious intent. It functions as a link farm, containing numerous URLs pointing to various domains, some of which are associated with compromised CMS uploads. The embedded URL `https://chcial.ru/uplcv?utm_term=root+mtk+devices+without+pc` suggests a potential phishing lure related to device manipulation. No scripts were extracted, but the PDF structure itself facilitates redirection to external, potentially harmful content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9849

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://chcial.ru/uplcv?utm_term=root+mtk+devices+without+pc PDF link annotation
    • http://unite-chem.cn/upload/files/zajefibuxugimoralabupedus.pdfIn PDF document text
    • http://lso-msm.com/userfiles/file/gipuvelodugato.pdfIn PDF document text
    • http://www.jobsincrete.gr/images/_user_na/file/pumetunobuwavadit.pdfIn PDF document text
    • https://trieurodata.ro/images/file/77511370766.pdfIn PDF document text
    • https://bibonatura.com/ckfinder/userfiles/files/xexisa.pdfIn PDF document text
    • http://abwessex.com/uploads/files/65187338908.pdfIn PDF document text
    • http://cayxaotamphan.net/userfiles/image/file/ninidexulan.pdfIn PDF document text
    • https://bushregenerators.info/userfiles/files/72648827593.pdfIn PDF document text
    • http://rockpapersun.com/upload_mce_image/file/dadaz.pdfIn PDF document text
    • http://speckrepej.com/upload/file/japuwavatafun.pdfIn PDF document text
    • http://ladispensadicampagna.it/uploads/assets/file/26327465761.pdfIn PDF document text
    • http://cgt-fo-csc.fr/wp-content/plugins/formcraft/file-upload/server/content/files/1612ed60a5eec8---89873827159.pdfIn PDF document text
    • http://podlahyadvere.sk/editor_uploads/system/files/foboxupakofubuwuzumanipum.pdfIn PDF document text
    • http://conflictfreeelectronics.com/ourprojects/chowki/UserFiles/renuka/file/vuduxonalubujit.pdfIn PDF document text
    • http://www.chiringuitomediterraneo.com/ckfinder/userfiles/files/61410911753.pdfIn PDF document text
    • http://giasudaihocsupham.com/Images_upload/files/87138012073.pdfIn PDF document text
    • http://chuanghuilaw.com/filespath/files/20210914075902.pdfIn PDF document text
    • http://huichem.com/ckfinder/userfiles/files/fusokosaruwovukexit.pdfIn PDF document text
    • http://gordostcrista.ru/userfiles/file/47376164565.pdfIn PDF document text
    • https://certifiedmoversinc.com/wp-content/plugins/super-forms/uploads/php/files/ebc821837b59208be3fda9e7c6fff4f9/1739201715.pdfIn PDF document text
    • https://heuresromantiques.com/upload/files/96348457642.pdfIn PDF document text
    • http://nanumed.ro/uploads/files/10078650520.pdfIn PDF document text
    • http://giovanniseneca.eu/userfiles/files/werupuzupidisexalapumove.pdfIn PDF document text
    • http://aptekadc.pl/userfiles/userfile/maxowowitonebexojagago.pdfIn PDF document text
    • https://bbensonmft.com/wp-content/plugins/super-forms/uploads/php/files/a24e8e75328b94dda87d3dfabcba1ce6/pomuxawozad.pdfIn PDF document text
    • http://ecole-belair.com/ecole/file/wezilebesirolomet.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_off0000b06d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xB06D 14972 bytes
SHA-256: f7a8cece19eeb03be1c48d74e256e31532ca3ff4c67994160e747856db194152
font_01_sfnt_off0000d614.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD614 10756 bytes
SHA-256: 2bdc19643d2f7f58ceff70090cf24e4a366c410c18647601766b09676aa83878
font_02_sfnt_off0000eeec.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xEEEC 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1