Malicious PDF — malware analysis report

Static analysis result for SHA-256 90e797f94d9bbaa8…

MALICIOUS

PDF

90.3 KB Created: 2021-04-25 19:56:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 99ca5aae53af4b94197aeb2774463e13 SHA-1: 708945aec3f4ff495706b6aec34803e4d63a4a9b SHA-256: 90e797f94d9bbaa8bdea9e24edfde704a9ef4d7a52e6c01edbfcf80e297b60d5
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1059.007 JavaScript

This PDF file was detected as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, many of which point to disposable hosting and redirectors, suggesting a link farm designed to distribute malware or conduct phishing. The primary malicious URL identified is https://dafemum.ru/strik, which is likely used to serve a second-stage payload.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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 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.
  • 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.
  • 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://dafemum.ru/strik?utm_term=sony+alpha+a77+ii+digital+slt+camera+body In PDF document text
    • https://cdn-cms.f-static.net/uploads/4413987/normal_605c5aa61e180.pdfIn PDF document text
    • http://electorat.org/judelugebo8hd47.pdfIn PDF document text
    • https://zikawudewodag.weebly.com/uploads/1/3/4/5/134585044/zolepub.pdfIn PDF document text
    • https://gugedawojovo.weebly.com/uploads/1/3/4/5/134590720/dekobopowef-vurepojamipube.pdfIn PDF document text
    • http://acupofjacob.com/space_harrier_32x_romxrgg4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4488570/normal_602304b77053f.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4443341/normal_601bfb4523015.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4415543/normal_5ffb5a6b95003.pdfIn PDF document text
    • https://rexekimat.weebly.com/uploads/1/3/4/0/134017736/xifetuzigevu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4451945/normal_60370c7e62a39.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4416512/normal_5ffa887ce6d92.pdfIn PDF document text
    • http://mon-cmbretagne.com/nilifujezimop8m.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4493888/normal_60579d5f24337.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://pazatirademe.rf.gd/costco_holiday_shopping_guide.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cfd090c2-2afe-405d-8938-d0ef16fd5aeb/proof_math_definition.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/55c5e4fb-f210-4565-ab3f-8c7cf4807eb1/voyager_diana_gabaldon_summary.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e7c2100c-f02f-4bb7-8f0b-63cfa7cfce2c/bebemuxemuzavenupes.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e89d375c-d80a-49a3-9ce7-b2280de0a4f0/how_to_start_a_fantasy_sports_business.pdfIn PDF document text
    • http://suferipuwa.epizy.com/26298344683.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://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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000109c1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x109C1 5912 bytes
SHA-256: 27a2e39493e9c35cf7dfd4ded5cbc065e2d62a40016b39737c8266774535ff64
font_01_sfnt_off00011dc4.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11DC4 11892 bytes
SHA-256: b126b49f6c10d09e0b5589589212ed16b34fbf9e1401f456c2bd54c065765c73
font_02_sfnt_off00014655.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x14655 16204 bytes
SHA-256: e93acd332f5893643511f4cefd38969ad5c744ad1b08842a788b6be7d277dd15