Malicious PDF — malware analysis report

Static analysis result for SHA-256 c3a3d891fa895fc6…

MALICIOUS

PDF

78.4 KB Created: 2021-04-11 12:48:49 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 82e5b34c212b5cf804b28006ad2c459b SHA-1: e2e65cbccf41a823786d1d7f1558cdacb37bac80 SHA-256: c3a3d891fa895fc607002c28176af5b6147126e546a78586a19959440149359a
126 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, indicating a link farm or SEO spamming operation. The heuristic 'PDF_SEO_LINK_FARM' and 'PDF_SEO_DISPOSABLE_LINK_FARM' strongly suggest this malicious intent. While no scripts were explicitly extracted, the presence of embedded URLs and the ML classifier's high confidence score point towards a malicious document, likely intended to redirect users to potentially harmful content or malware.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://nipisod.ru/strik?utm_term=omron+model+hem-711dlx PDF link annotation
    • http://de-bewertung-id2842384.icu/candy_crush_soda_saga_apk_for_pcpej3t.pdfIn PDF document text
    • http://findssldz.xyz/fisher_price_swing_snugapuppy_reviewz0u3f.pdfIn PDF document text
    • http://dapajurop.mygamesonline.org/trumpet_sheet_music_easy.pdfIn PDF document text
    • http://vijexibat.mywebcommunity.org/41309370048.pdfIn PDF document text
    • http://sinanomi.22web.org/40358941263.pdfIn PDF document text
    • http://gavediteriremuv.medianewsonline.com/function_notation_practice_worksheet_answers.pdfIn PDF document text
    • http://gexopidikimo.mygamesonline.org/lewis_structures_worksheet_with_answers.pdfIn PDF document text
    • http://fovoxarofej.getenjoyment.net/26338312738.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://wokoxut.epizy.com/puxugilanilanajome.pdfIn PDF document text
    • https://f2182bdb-ca8e-4fe7-b379-f84e14eeb57e.filesusr.com/ugd/026bcc_0b91af035d03483fbe8f4af661bd5174.pdf?index=trueIn PDF document text
    • http://kixixiwibatogit.epizy.com/pazebesoviretexaxuxezak.pdfIn PDF document text
    • https://b5526579-b22d-45a0-8251-9885a72cf3eb.filesusr.com/ugd/0cd019_5dc6bdcbc6954a9cbd291c65feeb4950.pdf?index=trueIn PDF document text
    • https://d09251a9-b09e-4077-8ccb-24037f005f7b.filesusr.com/ugd/a6ce17_d391f19bdf294778b225e6696fdb14d6.pdf?index=trueIn PDF document text
    • https://f635e5d9-31b1-4f19-b758-7a623be10181.filesusr.com/ugd/6cf0f5_4c93c5e5c3b24da486f0d9c8a89031a3.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/71c88aba-62b4-4868-aae5-cae70473eeb0/16206733794.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f3015e5c-3a08-48a9-b9f3-397889350506/mulof.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9f95c785-a8b4-43c0-b376-0796d7998a82/medical_sociology_14th_edition.pdfIn PDF document text
    • https://dd7ee03d-3646-4e01-a1e1-4c0a7e2c9e57.filesusr.com/ugd/d7ba0f_e165d1518fd64c6c9f6e076b7156ab49.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/9b445a67-9e71-43b6-b586-8947031ee9e4/kexodizifavovivekaneku.pdfIn PDF document text
    • https://cd489911-dc6d-4439-b408-84622343fb93.filesusr.com/ugd/d8e941_ccf22c24b7344fc1b073d5b31b8e0f75.pdf?index=trueIn PDF document text
    • https://29aa9d28-cc9d-45fc-8d86-3718b5881c84.filesusr.com/ugd/74c34a_cc7d6f0cf84a4e5fa07850876b353d03.pdf?index=trueIn PDF document text
    • https://a9864912-ad24-422b-99f3-2d90f7703507.filesusr.com/ugd/d6af85_57eab59c36b4471ca3fe32332a0e939c.pdf?index=trueIn PDF document text
    • http://ninalosuza.rf.gd/lewedenaterofevukuv.pdfIn PDF document text
    • http://vanuragevexofe.rf.gd/23399118925.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_off0000f49d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF49D 4936 bytes
SHA-256: 76e98d00b553714a45b792671fc3a1d928fd04e968eec0af545d1108e60d35fa
font_01_sfnt_off0001054e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1054E 11352 bytes
SHA-256: e03b6005b9171a7e5a8fed36ef1b6f8faeedcf07de28ebbccf09021cb8451b95