Malicious PDF — malware analysis report

Static analysis result for SHA-256 ac71e8fff117493b…

MALICIOUS

PDF

78.3 KB Created: 2021-04-07 19:23:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 61d113b2a58617fd8dbad1dd06c9f629 SHA-1: 7c0dc582dfcfcd8a55cebd705da64b5bcbbd7f43 SHA-256: ac71e8fff117493b0b7bbd8e8b4ec6812fb824bf83b7a703e4dc83fca69dba6f
126 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO manipulation tactic. The ML classifier strongly flagged this PDF as malicious. While no scripts were explicitly extracted, the PDF structure and embedded URLs suggest it's designed to redirect users to potentially malicious content or phishing sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9964

Heuristics 5

  • 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://vilenefex.ru/123?utm_term=abacus+workspace+software+free PDF link annotation
    • http://nufudaluwunuja.22web.org/zivunabupijini.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450347/normal_601e648574be5.pdfIn PDF document text
    • http://alsamcctv.com/116312731723gjix.pdfIn PDF document text
    • https://fidagavatijib.weebly.com/uploads/1/3/1/3/131398583/xalakazuxod.pdfIn PDF document text
    • http://yoptan.space/12057245701m1mli.pdfIn PDF document text
    • http://evromotors.net/bn_racing_mod_apkbd4pm.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4445877/normal_5ffcabac2c579.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4385631/normal_60090263ce061.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4466154/normal_5fe08c08225e2.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4493867/normal_5fcdd84b37892.pdfIn PDF document text
    • http://zhenskiizhurnal.ru/brazilian_wish_bracelet_color_meanings1yhaa.pdfIn PDF document text
    • https://jafovoguna.weebly.com/uploads/1/3/4/0/134096268/54c07a.pdfIn PDF document text
    • http://sayfelengs.space/monster_pop_bubble_shooter_games_downloads7cxk.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://edcb5511-827b-40b0-97c1-3499c313f96b.filesusr.com/ugd/0779a3_56d1831ef6ed4761b944ffc356b7be3f.pdf?index=trueIn PDF document text
    • https://02e0da19-eac5-4521-950b-4e410541bf1c.filesusr.com/ugd/516249_1b8fe8633d664828a6a7a4efe9af1082.pdf?index=trueIn PDF document text
    • https://4ab51db4-2ab9-4ce7-8cf9-a7235cd4f8a6.filesusr.com/ugd/c6359c_779dd70a2685486281f53d6a2bd71ad5.pdf?index=trueIn PDF document text
    • http://wasukux.rf.gd/11014394343.pdfIn PDF document text
    • https://11484d69-1612-41b9-9199-165df1f08223.filesusr.com/ugd/e2f197_425858c6462445f6bdb60cfa01e076f7.pdf?index=trueIn PDF document text
    • http://tanozetodane.rf.gd/riduwekeb.pdfIn PDF document text
    • http://pijedawometuzov.epizy.com/poluf.pdfIn PDF document text
    • https://d52aed46-be45-4f9b-8106-cf6fc7ee66c0.filesusr.com/ugd/b148e5_8f89810146484ee3a2f3e812ab656271.pdf?index=trueIn PDF document text
    • https://724418e0-3ace-43c1-abd8-628b4820fc71.filesusr.com/ugd/6df952_6c6af47b5def4ed695c19a3d950f210b.pdf?index=trueIn PDF document text
    • https://4f65501f-cdae-4966-b9db-49b15ad9d196.filesusr.com/ugd/52b593_9fc8e79ccf3f4a9db056e7a593fe35e9.pdf?index=trueIn PDF document text
    • http://folizel.epizy.com/blockly_games_maze_10_answer.pdfIn PDF document text
    • https://1423d76f-a56f-4481-bf87-726e17039346.filesusr.com/ugd/14aee2_74c56d00d2064f59a47024f1fb861010.pdf?index=trueIn PDF document text
    • https://c7fb3737-a2fb-4e06-b71d-f78b648bb0a4.filesusr.com/ugd/a9248e_77a9a87d02bc422ea49102a1ddbd1e53.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_off0000f3af.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF3AF 5260 bytes
SHA-256: de9dfd55a9a0a4ab52b1798435e959e486dfb66b6374b25d6c055b16ab4f8f5f
font_01_sfnt_off000105b8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x105B8 11184 bytes
SHA-256: 16ab272f5ac35ccade0beae8efca75f4f51d5f3b4690245ce1d4cd7b5ae10d31