Malicious PDF — malware analysis report

Static analysis result for SHA-256 992acdf46f9ef1a0…

MALICIOUS

PDF

73.9 KB Created: 2021-04-26 15:59:03 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-08-20
MD5: 8cd9de8f4e2d8f4e14826cb2d20b5f9f SHA-1: 23455411b4cc060c6725e3bcac1dacc73cf56859 SHA-256: 992acdf46f9ef1a0bc55dd7a8e2789d0c6a1a35ace96c7365fe133848106951b
254 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic firing indicating it redirects to known malicious infrastructure. The document body, though heavily obfuscated, appears to be a lure related to engine diagrams. The primary malicious URL identified is dafemum.ru, which is used in a redirector scheme.

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
  • 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.
  • Image lure linking to an SEO redirector (free-download phishing) high PDF_SEO_UTM_REDIRECTOR_LINK
    PDF embeds an image with little or no body text and a clickable link to a multi-word utm_term / FeedBurner-proxied SEO redirector — the 'free ebook / solution-manual / document download' phishing family that ranks for natural-language search queries and routes the user into a payload/redirect chain. The PDF carries no exploit; the risk is the linked destination. Flagged structurally (image lure + SEO redirector) so it does not depend on a ClamAV/ML signature, and regardless of how many filler text pages the lure carries.
  • 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://dafemum.ru/strik?utm_term=briggs+and+stratton+450+series+engine+diagram In PDF document text
    • https://static.s123-cdn-static.com/uploads/4460694/normal_5fc8de84befa0.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4487663/normal_606e85bc35860.pdfIn PDF document text
    • https://cdn.sqhk.co/renonidofel/4hJjjj0/zekotakewipekinega.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4388413/normal_60636a3427802.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4409840/normal_603c437e39a1f.pdfIn PDF document text
    • https://cdn.sqhk.co/xevezele/kQQgfgg/adidas_nmd_white_and_gold.pdfIn PDF document text
    • https://cdn.sqhk.co/gimexigerub/mHtajjf/gowuduseforofude.pdfIn PDF document text
    • https://tajuboramaze.weebly.com/uploads/1/3/4/5/134591815/3620095.pdfIn PDF document text
    • https://tidosivapozagul.weebly.com/uploads/1/3/4/3/134390518/1769068.pdfIn PDF document text
    • https://cdn.sqhk.co/letarezetap/CsaOhdD/77800013952.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://s3.amazonaws.com/gedimuta/2603387312.pdfIn PDF document text
    • https://s3.amazonaws.com/zagapaxa/zavisovuxu.pdfIn PDF document text
    • https://631ffb88-cf2d-4844-8d6b-9338a1b21cc5.filesusr.com/ugd/d24e6f_82b965baa709424183d16efb3e0f59bd.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/widiku/what_does_a_white_raven_mean.pdfIn PDF document text
    • https://7be8961d-effb-4c78-a255-78c3c9f0be09.filesusr.com/ugd/3dd68e_b8133c2529dc440abd1c2ca33fb11f6c.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/kulinisokakewi/how_to_protect_my_app_from_reverse_engineering.pdfIn PDF document text
    • https://s3.amazonaws.com/sabobenuwe/fluke_87_iii_manual.pdfIn PDF document text
    • https://3228dc58-b2c1-4aed-ac20-03fc52793822.filesusr.com/ugd/43afbb_bb11514c5954468b9e12eb320693990b.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/daxemo/how_to_troubleshoot_compressor_in_a_refrigerator.pdfIn PDF document text
    • https://6ec3981f-6443-463b-a164-91fc69f101d9.filesusr.com/ugd/7603ae_e346b749b89b44a9975e7849db661f3e.pdf?index=trueIn PDF document text
    • https://s3.amazonaws.com/wolina/psychedelic_furs_ghost_in_you_sheet_music.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_off0000dfc6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xDFC6 5516 bytes
SHA-256: 5ea665be777bc8691cb60d6caf18e6a9d300da144442fe800a69d80555f40b97
font_01_sfnt_off0000f281.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF281 10956 bytes
SHA-256: 69868cbe8004813277767e3f8a5519d4ecc0c0a567d7c19a5ac3fdc3dcb8385a