Malicious PDF — malware analysis report

Static analysis result for SHA-256 ff6795cc51a0edcc…

MALICIOUS

PDF

68.0 KB Created: 2020-11-24 07:58:35 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 58f59a333ef0ef75494882d3a2104544 SHA-1: 5d0af621d27519cf53c16ed88a7a83869e6a2d17 SHA-256: ff6795cc51a0edcc55804a81c4784365d8856a7bfb8658cb7cd970f89dca0427
244 Risk Score

Malware Insights

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

This PDF file contains a large number of embedded links, many of which point to external PDFs hosted on disposable domains. The primary heuristic firings indicate this is a malicious redirector and a link farm, likely for SEO manipulation or to distribute further malicious content. The ML classifier and ClamAV detection strongly support its malicious nature.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 6

  • 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.
  • ClamAV: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://ggtraff.ru/aws?utm_term=google+sheets+count+merged+cells
    • https://cdn-cms.f-static.net/uploads/4403680/normal_5f97b72f2cc03.pdf
    • https://cdn-cms.f-static.net/uploads/4409621/normal_5f989d3303ef0.pdf
    • https://visajemilami.weebly.com/uploads/1/3/4/2/134265887/resopawaluf.pdf
    • https://wokepugef.weebly.com/uploads/1/3/4/9/134901336/7d88640b20.pdf
    • https://jamafijuzu.weebly.com/uploads/1/3/1/4/131437216/gabavepaximiv.pdf
    • https://povutepumik.weebly.com/uploads/1/3/2/7/132741486/2769223.pdf
    • https://cdn-cms.f-static.net/uploads/4376621/normal_5fa540932c8da.pdf
    • https://tarirubawapub.weebly.com/uploads/1/3/1/6/131606173/1009128.pdf
    • https://kizozejibudi.weebly.com/uploads/1/3/4/4/134460324/227259.pdf
    • https://tolixolosunep.weebly.com/uploads/1/3/4/4/134403343/rukulivo_ladoj_buxivejevom.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/736cafef-6dff-4cb4-9f6b-62768a4bdc30/nylon_flexible_partial_dentures.pdf
    • https://uploads.strikinglycdn.com/files/42bc5236-0910-4b05-982d-745027db8944/trenzas_para_nias_2020.pdf
    • https://uploads.strikinglycdn.com/files/71e1ea98-2718-4e03-b442-a39241c967a9/kukuzaduvi.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc92.bin
c6f1bac98810e563c50d27952ef5033f2dd1af8cdefe30c1e8d365b45a2bb9e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xCC92 5176 bytes
font_01_sfnt_off0000de08.bin
51fe17bd180e6b89768b6ddc261b60d261010347e6eef22f6818d41154779f67
pdf-font-stream PDF embedded font (sfnt) at offset 0xDE08 11024 bytes