Malicious PDF — malware analysis report

Static analysis result for SHA-256 633fdcfea1cf9bdf…

MALICIOUS

PDF

80.2 KB Created: 2021-04-06 23:27:58 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-07-02
MD5: 0fac922937e07d0ec4022c5fb006afec SHA-1: 5fe59d87876e3a3c9fd397ccddf919d3fe4facd7 SHA-256: 633fdcfea1cf9bdf64f638be7c4f98dd671825ebdfb5f2484b5374200b969d95
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many pointing to disposable domains, as indicated by the PDF_SEO_LINK_FARM and PDF_SEO_DISPOSABLE_LINK_FARM heuristics. The ML classifier and ClamAV detection strongly suggest malicious intent, likely related to phishing or distributing other malware. The embedded URLs and the document's structure point towards a link farm strategy, potentially for SEO manipulation or to host malicious payloads.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://nipisod.ru/award?keyword=arabic+language+history+pdf PDF link annotation
    • http://free-at.pro/the_three_estates_political_cartoon66iid.pdfIn PDF document text
    • http://freefire-gifts.com/what_is_the_difference_between_ppap_and_apqpm95xl.pdfIn PDF document text
    • http://digitalliteracyinstitute.com/xabofisekilefivuwumaw0tmt.pdfIn PDF document text
    • https://dubasatipin.weebly.com/uploads/1/3/4/4/134459773/tipaxukopo_bupovatixi_laxujur.pdfIn PDF document text
    • http://geosen.net/dun_and_bradstreet_small_business_credit_reportbsrgo.pdfIn PDF document text
    • https://kazumole.weebly.com/uploads/1/3/1/4/131454435/verujas.pdfIn PDF document text
    • https://pifabevab.weebly.com/uploads/1/3/4/7/134721676/7113686.pdfIn PDF document text
    • https://pofitefe.weebly.com/uploads/1/3/4/6/134617546/2da79.pdfIn PDF document text
    • https://wokawopirajer.weebly.com/uploads/1/3/3/9/133999547/348c66b750.pdfIn PDF document text
    • http://sandwichhq.club/37869149650wdrph.pdfIn PDF document text
    • https://jegokama.weebly.com/uploads/1/3/4/6/134651242/2859344.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://ac911ccd-a574-46a9-bbb3-57bb927ff796.filesusr.com/ugd/2735c9_a4ed7f3b860340d5a08861d991c12138.pdf?index=trueIn PDF document text
    • https://8dac4d01-2cd1-45d2-8b5f-6005f802adc9.filesusr.com/ugd/1f96ce_ad17c37fb0ea45faa00979d862f04c3f.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/481bf997-e8f2-4d68-8ef4-ad5d0452d72e/44532930969.pdfIn PDF document text
    • https://ebed6276-6372-4ddf-adad-9a0fa504b99f.filesusr.com/ugd/805d2a_aa81c6c3edb14cdea50f4399bac28634.pdf?index=trueIn PDF document text
    • https://8fc1c2d6-49ba-4d63-8b95-0327ef2b1627.filesusr.com/ugd/1849a1_79d1f5bdb72e4f9c932ec52754b05518.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/71a81c13-e434-4158-a4f8-fc9dd8479824/craftsman_lt2500_manual.pdfIn PDF document text
    • https://3e3188f7-d9e9-48da-9af6-4e6760718ee0.filesusr.com/ugd/4f7562_429a2e98346b47f89b9dbbc0377dcab7.pdf?index=trueIn PDF document text
    • https://4bf641bf-117a-4913-931f-55e49063997f.filesusr.com/ugd/5befcb_5d93ead42216415591b898a937f82480.pdf?index=trueIn PDF document text
    • https://571cbd0a-ba82-408d-be6d-2df53a8fcfe5.filesusr.com/ugd/02af14_4d0fd3ece4d74fe49c444fc13ec6bb61.pdf?index=trueIn PDF document text
    • https://807eaacf-9fb6-4e16-bcb8-061395d1d132.filesusr.com/ugd/a3ef2e_63e9641841fa4a0d859fb58236b9fd63.pdf?index=trueIn 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_off0000fb63.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFB63 5648 bytes
SHA-256: 8293e779a7b6433f19215acb07f4fc201cb16664d70fa1710247395070e143dd
font_01_sfnt_off00010e90.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10E90 10936 bytes
SHA-256: 8faeb9357a0523def4bdc999b317d40bc427868d41940592dcdf224fd4dcdf58