Malicious PDF — malware analysis report

Static analysis result for SHA-256 d90c149636b634f5…

MALICIOUS

PDF

82.4 KB Created: 2021-09-17 15:44:39 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3) First seen: 2021-10-14
MD5: d17f1a8adf7623d17af56ae55e4067d2 SHA-1: fca9ffc3db0abe7a537d2a0d540199d79674a524 SHA-256: d90c149636b634f59af87e35f64ff649909345074de5b0ca435087d533801b94
156 Risk Score

Malware Insights

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

The file is identified as a malicious PDF by multiple heuristics and an ML classifier, with ClamAV detecting it as a phishing trojan. It contains a large number of embedded URLs, many of which point to compromised WordPress sites or disposable hosting, forming a link farm. These URLs are likely used to redirect users to malicious content or phishing pages.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9985

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://laborke.ru/uplcv?utm_term=black+butler+season+2+episode+10 PDF link annotation
    • http://paolacaone.eu/userfiles/files/94227145309.pdfIn PDF document text
    • https://cupanghitam.com/contents/files/88097081486.pdfIn PDF document text
    • http://kenshopvn.com/uploads/files/54033967046.pdfIn PDF document text
    • http://luckyassessoria.com.br/wp-content/plugins/formcraft/file-upload/server/content/files/1613b82093808c---66370836565.pdfIn PDF document text
    • http://test-immo.com/file/xakunirenudede.pdfIn PDF document text
    • https://popcouncilinstitute.org/wp-content/plugins/super-forms/uploads/php/files/6a3357599e4c40c1ddeac7a8577d501d/24401849236.pdfIn PDF document text
    • http://zhongjiukeji.com/upload_fck/file/2021-9-6/20210906032446423820.pdfIn PDF document text
    • http://tiwtactic.com/userfiles/files/duwukomepekivekeguderit.pdfIn PDF document text
    • https://digireg.cz/upload/mejunetisaku.pdfIn PDF document text
    • http://sameiroeventos.pt/ficheiros/79242995608.pdfIn PDF document text
    • http://makassitools.com/userfiles/file///14339316076.pdfIn PDF document text
    • http://kmbb.at/userfiles/file/9864362723.pdfIn PDF document text
    • http://tlxzkj.com/uploads/file/0714164068.pdfIn PDF document text
    • http://vanillasky-ch.com/images/files/95832830211.pdfIn PDF document text
    • https://solener.info/ckfinder/userfiles/files/74683095471.pdfIn PDF document text
    • http://jmestateplanning.com/customer/3/d/9/3d947ad6ce2568d98b832ccf5548371bFile/24353090731.pdfIn PDF document text
    • https://regenerateacademy.com/file/fadogolovawiganatedamat.pdfIn PDF document text
    • https://hometutorsdelhi.com/userfiles/files/67787242705.pdfIn PDF document text
    • http://aihyang.com/userfiles/file/51142407912.pdfIn PDF document text
    • https://www.physioaktivkramer.de/wp-content/plugins/formcraft/file-upload/server/content/files/161324701baf1e---58215046834.pdfIn PDF document text
    • http://mikomisushiwc.com/uploads/files/15486378709.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_off0000db58.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDB58 16792 bytes
SHA-256: 9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
font_01_sfnt_off0000f36a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF36A 18064 bytes
SHA-256: 526d6f5c305e4008ec950e51cd4368a46402be168ab4571415370356742845ef
font_02_sfnt_off000121f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x121F9 11184 bytes
SHA-256: f1c926058803b83d03bf6c6e96dce97ab5f927fe7763ad891f5c487308134bbc