Malicious PDF — malware analysis report

Static analysis result for SHA-256 b8fb15e64e890d70…

MALICIOUS

PDF

83.1 KB Created: 2021-03-14 08:17:50 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-06-17
MD5: 9551433438dd61e400f73cfb1fd2fd4a SHA-1: 91446d082901f4e21e18c9af1b75247b773c0a3b SHA-256: b8fb15e64e890d70c2fecc81b8317b86f5298bd0d92dca4de8c0836af6ad2fb4
186 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. It contains a link farm with numerous external links, including one to `jottigo.ru`, suggesting an attempt to redirect users to potentially harmful content. The document body, though heavily obfuscated, appears to be related to a worksheet, which is a common lure for phishing or malware delivery.

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
  • 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.
  • 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://jottigo.ru/wix?keyword=math+about+me+worksheet+1st+grade PDF link annotation
    • http://giocodigital.fun/vudenq0ud5.pdfIn PDF document text
    • http://imkl-checker.com/mobowovomavexubafsmocj.pdfIn PDF document text
    • http://gromstroy.com/dell_1610_hd_lamped4tcl.pdfIn PDF document text
    • http://train-home.ru/26662556858kvsoe.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/acff6db0-95ee-4393-9de9-3dba27244082/51946285887.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/cef61920-a198-44e1-b41e-d3cbcc6a6d1c/53982675871.pdfIn PDF document text
    • https://s3.amazonaws.com/redegelesibif/14076596425.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b7961cb4-e7b9-4cd5-8414-7a324a47f72e/how_to_program_rca_remote_to_lg_tv.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8fb72ec7-df41-498d-8574-80d04f2500b4/11632977976.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/797458e0-e79c-4db3-a6a9-b2aad5606f59/zuxokuxikare.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b470e396-5fcf-49e3-8887-507031fa4956/vezobixipugum.pdfIn PDF document text
    • https://73af689e-4c80-4f62-99d3-7a886641ad81.filesusr.com/ugd/3b5dd9_e8b3a046da5b4eb9b6a388aeaf3b80f9.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/23148ddb-3660-4373-bcc6-805fbbc4d5ab/who_is_the_white_tiger_on_masked_singer_season_3.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/174b7909-5eae-4530-bdd3-1e1d90844202/sunusipibasorujulo.pdfIn PDF document text
    • https://fccd5518-64e1-462d-9dbe-8d8d8a19ca7a.filesusr.com/ugd/eb005d_c4185cbc2e484d579c43160d157133e6.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/7e582677-a767-42ea-8711-233324dee9a6/what_are_the_best_computer_programming_languages_to_learn.pdfIn PDF document text
    • https://dacf5b84-f80e-4bd8-bb7f-22aad20a1cd8.filesusr.com/ugd/285be4_cf77e990e7664e65a747823e2f48c9a0.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/ed3852b7-e677-44ee-9b61-fc36f98bdc0f/pibumemidijow.pdfIn PDF document text
    • https://8c1dc56a-a131-4b43-acff-3635b9115217.filesusr.com/ugd/90423f_b14e7e168c1a4be5bc96d6ce19c9be7b.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/genukopapovixo/apsc_computer_operator_admit_card_2019.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

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00010552.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10552 5560 bytes
SHA-256: 450dcfe42082a871357b480a376197a268c3ed9e84b5f5bd5254d6621b8b7280
font_01_sfnt_off00011830.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11830 11372 bytes
SHA-256: 56b9785a068e57625adda57387b0616cf06b122820dc7fa1365d068782399e4c