Malicious PDF — malware analysis report

Static analysis result for SHA-256 f9d95cc8dd6d5e61…

MALICIOUS

PDF

83.4 KB Created: 2021-05-20 17:06:37 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: ae45c7e4f9b8b85d05865a2492d1d90a SHA-1: 9eeca8cc7f166302966fe77f054ed1b35882a7dd SHA-256: f9d95cc8dd6d5e6101a2aef24f7c4d25fc278cf17e47f726630690b9a18ee166
156 Risk Score

Malware Insights

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

The PDF contains numerous external links, with a critical heuristic identifying it as a 'PDF_SEO_LINK_FARM'. One of the primary external URIs, 'https://pelibifir.ru/strik?utm_term=what+is+the+best+free+keto+diet', is flagged as suspicious. The ML classifier and ClamAV also strongly indicate maliciousness, with ClamAV identifying it as 'Pdf.Phishing.Trojan'. The document body is heavily obfuscated, but the presence of external links and the heuristic firings suggest a phishing or malware distribution attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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.
  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://pelibifir.ru/strik?utm_term=what+is+the+best+free+keto+diet
    • https://vegilirebaj.weebly.com/uploads/1/3/1/0/131070576/2097968.pdf
    • https://budojidotepaso.weebly.com/uploads/1/3/5/3/135312143/xaxezen_xirefoxunofuru_jomaseko.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/595e3890-6265-466a-b1d1-65d9e46c1a91/how_to_fix_damaged_nail_bed.pdf
    • https://uploads.strikinglycdn.com/files/1a044f26-b846-492f-b7a3-08f7fd3517a0/after_the_last_olympian_fanfiction.pdf
    • https://uploads.strikinglycdn.com/files/37e41efd-4fba-4100-9a47-80feecb0ef68/what_is_the_rainy_season_in_cancun.pdf
    • https://uploads.strikinglycdn.com/files/821953bd-0a78-438e-9941-b489d23debd2/mbti_test_reliable.pdf
    • https://uploads.strikinglycdn.com/files/dccec200-2f03-44da-b7b3-2d5f427bc21b/ariens_snowblower_oil_recommended.pdf
    • https://uploads.strikinglycdn.com/files/ea801a75-fc9c-434e-927d-3fbf4fb4d910/23296567798.pdf
    • https://uploads.strikinglycdn.com/files/f156c8cb-5011-4c3a-b4a3-20d3527d2657/82676624042.pdf
    • https://uploads.strikinglycdn.com/files/cbfd5290-233f-470f-9345-ba88b7900512/what_is_the_best_starbucks_drink_to_wake_you_up.pdf
    • https://uploads.strikinglycdn.com/files/e80b61ee-a452-4dbe-bf37-4c61314c44b9/emglo_e810-4v_air_compressor_parts.pdf
    • https://uploads.strikinglycdn.com/files/91be6b96-b9ed-4e72-b3c2-c8b04da97be9/17206894684.pdf
    • https://uploads.strikinglycdn.com/files/fa32b0af-e7f3-4a68-b99d-2ab9fc60f10f/51528328247.pdf
    • https://uploads.strikinglycdn.com/files/ca1d4bb7-d720-4d05-b3b3-84a195ebeb21/mibisugegobibe.pdf
    • https://uploads.strikinglycdn.com/files/1deaca04-ce5f-4bcf-b105-1c1caa2c0825/sezusozubaradizapojajizil.pdf
    • https://uploads.strikinglycdn.com/files/ccf4315e-35b3-486d-889f-38226afe00a0/stairway_to_heaven_kdrama_ost.pdf
    • https://uploads.strikinglycdn.com/files/186c423b-2504-4802-9169-e38a492e6abc/shooting_games_unblocked_wtf.pdf
    • https://uploads.strikinglycdn.com/files/aadcd146-a483-4f64-994a-bf763e1c4662/14309134473.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://scripts.sil.org/OFL

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off000108c2.bin
075e626584bc7b5b51c066286430a127349b554450cef8f7d4613feb045d7641
pdf-font-stream PDF embedded font (sfnt) at offset 0x108C2 5180 bytes
font_01_sfnt_off00011a65.bin
a71b49952d40b36081631ab8b75f0678043029d6b8edc53afa74d6953e077a57
pdf-font-stream PDF embedded font (sfnt) at offset 0x11A65 10720 bytes