Malicious PDF — malware analysis report

Static analysis result for SHA-256 ca8abdc32394cbb1…

MALICIOUS

PDF

77.4 KB Created: 2021-04-14 23:21:44 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: e1f5db43b275597a0fab579b87a2b8bd SHA-1: b8b651c9cb0f28624f9f49c9881c72350b123cf2 SHA-256: ca8abdc32394cbb1aba7ba689aea58e9ef6023548ae041467451ca89033ddf17
156 Risk Score

Malware Insights

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

This PDF file was flagged as malicious by ClamAV and an ML classifier, indicating a high likelihood of malicious intent. It contains a large number of external links, with one pointing to 'https://kuzutuzo.ru/strik?utm_term=how+to+use+a+barrel+stove', suggesting a link farm or phishing lure. The presence of embedded URLs and the PDF_SEO_LINK_FARM heuristic indicate the document's primary purpose is to redirect users to potentially harmful external sites, likely for credential harvesting or further malware delivery.

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-d2568dad23a94d95-d2568dad23a94d95-10044375-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2568dad23a94d95-d2568dad23a94d95-10044375-0
  • 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://kuzutuzo.ru/strik?utm_term=how+to+use+a+barrel+stove
    • https://wurilulisewanid.weebly.com/uploads/1/3/4/7/134728532/7d6c62de7c.pdf
    • https://cdn.sqhk.co/fepexeguma/if3U53i/ducks_basketball_team.pdf
    • https://cdn-cms.f-static.net/uploads/4369328/normal_604aca438d312.pdf
    • https://cdn-cms.f-static.net/uploads/4460048/normal_602d5108dfb09.pdf
    • https://cdn.sqhk.co/zifegowuf/Dgdhbid/torn_rotator_cuff_surgery_recovery.pdf
    • http://lijamerogavex.iblogger.org/differential_topology_guillemin.pdf
    • https://cdn-cms.f-static.net/uploads/4365545/normal_603247762a9c3.pdf
    • https://pegiromilu.weebly.com/uploads/1/3/4/6/134683304/2b51435f78f913.pdf
    • https://ramakizuwag.weebly.com/uploads/1/3/4/3/134321509/tejokapeka.pdf
    • https://toverumu.weebly.com/uploads/1/3/0/8/130815437/9394487.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • https://uploads.strikinglycdn.com/files/01d2aeb3-ac45-4329-b2ce-b0ee052f865b/20411291743.pdf
    • https://uploads.strikinglycdn.com/files/8b75b21e-460f-400a-922c-d925ee5e32b8/how_much_does_a_school_counselor_make_uk.pdf
    • http://jajunegetilu.rf.gd/alkanes_examples.pdf
    • https://uploads.strikinglycdn.com/files/01de16b7-b4cb-4e78-87fa-c3cf3389d33c/77591256540.pdf
    • https://uploads.strikinglycdn.com/files/998f4253-ea3e-4681-a7e6-1b40548e09c0/what_kind_of_battery_goes_in_a_g_shock_watch.pdf
    • https://uploads.strikinglycdn.com/files/1de07d1f-f8fc-42c7-baf7-4ed118f2004c/who_is_the_first_person_translated_quran_in_english.pdf
    • http://gefafeduvul.epizy.com/dezivugar.pdf
    • https://uploads.strikinglycdn.com/files/ad04dc19-67cf-4977-8345-89d7f6c09697/52056522111.pdf
    • https://uploads.strikinglycdn.com/files/9dde0549-0773-4617-a5fd-8b0084cbf458/fejuvewewurawi.pdf
    • https://uploads.strikinglycdn.com/files/c39e3fb6-63b9-4c1a-908c-3ebf7c0c08f2/54438564654.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_off0000eef9.bin
1e5e0b06f84e2ac67136129509384d5a85dbfba88488f353b28f235d62ae09aa
pdf-font-stream PDF embedded font (sfnt) at offset 0xEEF9 4932 bytes
font_01_sfnt_off0000ffdd.bin
f22815ddd7745f86e74f71fee43a539fd2864271e3f3737e306bf5411470c789
pdf-font-stream PDF embedded font (sfnt) at offset 0xFFDD 11876 bytes