Malicious PDF — malware analysis report

Static analysis result for SHA-256 8633ec8b2d7a5ebc…

MALICIOUS

PDF

73.1 KB Created: 2020-11-28 09:41:58 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-10-26
MD5: 15d8925fa2a1f16931044edca7d5389b SHA-1: 1e535a3a074b90be9d0a545f52ebc52734e52250 SHA-256: 8633ec8b2d7a5ebc64f888879a867f71c93079e01f9b13c48abd3278443a4dbe
302 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution T1059.007 JavaScript

The PDF contains numerous links to external resources, including a known malicious redirector, and instructs users to disable security software. The ML classifier and ClamAV detection strongly indicate malicious intent. The presence of embedded URLs and the instruction to disable security software suggest an attempt to facilitate the download and execution of a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 8

  • 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 links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • Small PDF contains mass external PDF link farm critical PDF_SEO_LINK_FARM
    Small PDF contains many clickable external PDF links, mostly clustered on one host. This matches generated SEO/link-farm PDF carriers used to route users into malicious or unwanted-software delivery chains, rather than a normal document citation pattern.
  • LOLBin token sequence in document text high SE_LOLBIN_RUN_COMMAND
    Extracted document text contains a Windows script/execution tool name (PowerShell, mshta, cmd, rundll32, regsvr32, …) within 220 characters of a dangerous flag, command verb, or URL. This is a visible 'run this' instruction in HTML/PDF/RTF lure bodies, or — in macro-laden Office files — the macro's own string-pool entries appearing adjacent in extracted text.
  • Security software disable instruction high SE_SECURITY_BYPASS
    Document instructs the user to disable antivirus or security software — unusual for ordinary documents and high-risk in an unsolicited file
  • Visual download / call-to-action button lure low SE_DOWNLOAD_BUTTON
    Document contains a call-to-action phrase ('Click here to download', 'Download Now', etc.) — low-signal unless other findings point to a malicious workflow
  • 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://gettraff.ru/aws?utm_term=blacksad+pdf+free In PDF document text
    • https://demomejisalazi.weebly.com/uploads/1/3/4/8/134869482/fizez.pdfIn PDF document text
    • https://xexovelez.weebly.com/uploads/1/3/0/8/130813416/6a87a6a4a2594.pdfIn PDF document text
    • https://jipemovikeral.weebly.com/uploads/1/3/4/0/134012889/pagepa_mezulezerixeli_bofofefugexeb.pdfIn PDF document text
    • https://pozosukezogi.weebly.com/uploads/1/3/4/3/134386022/fawidenakuzor-wazosaxojo-takol-wefuzozi.pdfIn macro / runtime command snippet
    • https://xujaxivef.weebly.com/uploads/1/3/1/4/131438557/8b7ed9afed.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/bifadiwuwileji/42902509102.pdfIn PDF document text
    • https://s3.amazonaws.com/padadutiseni/towigulizegalererov.pdfIn PDF document text
    • https://s3.amazonaws.com/zoromexemuzid/rosesiru.pdfIn PDF document text
    • https://s3.amazonaws.com/tobobowu/bicep_barbell_curl_form.pdfIn PDF document text
    • https://s3.amazonaws.com/kawotexulozax/asus_x553m_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/320ae1e4-69f1-4d9f-8acb-276859a06f32/hp_probook_4520s_drivers_update.pdfIn PDF document text
    • https://s3.amazonaws.com/buwosevax/sebimosezukizajamogol.pdfIn PDF document text
    • https://s3.amazonaws.com/wajufifenoxuj/development_economics_todaro.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
    • https://s3.amazonaws.com/kawotexulozax/asus_x5In macro / runtime command snippet
    • http://scripts.sil.org/OFLIn PDF document text
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c34b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xC34B 5260 bytes
SHA-256: 5aca7940c07b6241805c72426c06cb66afc63ff8fd5b7a97c6e30c5635540154
font_01_sfnt_off0000d53a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xD53A 1800 bytes
SHA-256: e9a5a1f6ed95b1e3669933bb00002ad32a1708c3e0b735191cad5e02368a6c7d
font_02_sfnt_off0000ddc8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDDC8 10672 bytes
SHA-256: 91310fd17103feb31c1b67fcbc21e391afe548183875ead0251ea37ae1072346
font_03_sfnt_off00010267.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10267 16164 bytes
SHA-256: 9026f3b3db4823843c0cd60ab9659202f9f06131997374a39278b243e9da0b8e