Malicious PDF — malware analysis report

Static analysis result for SHA-256 40cbd8095f58d63f…

MALICIOUS

PDF

77.8 KB Created: 2021-06-07 02:43:22 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: 2bba28c5012466e020d4b803c6813304 SHA-1: 33ea7d5a5c9ab879847b6203a0fe7f5c9553c155 SHA-256: 40cbd8095f58d63f7d45026bee7d776c16233835fc2de9845d223a865c1f9109
186 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a large number of external links, many pointing to disposable domains, indicative of a link farm. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or SEO spam. The primary URL identified is https://catamma.ru/pbw?utm_term=is+gcse+equivalent+to+b1+cefr.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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
  • 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://catamma.ru/pbw?utm_term=is+gcse+equivalent+to+b1+cefr PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4388156/normal_602a77f5ed118.pdfIn PDF document text
    • https://ruxunomitebapat.weebly.com/uploads/1/3/1/6/131606858/1968773.pdfIn PDF document text
    • https://baluwona.weebly.com/uploads/1/3/4/6/134611665/ea2cd6531062.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4476783/normal_602551231e73b.pdfIn PDF document text
    • https://wozuxepu.weebly.com/uploads/1/3/4/4/134478893/wixemorimejejag-pegerivun-totab-zofusal.pdfIn PDF document text
    • https://lexodedibipi.weebly.com/uploads/1/3/4/6/134683920/rogagukexa.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4388183/normal_5ff685989684c.pdfIn PDF document text
    • https://disomigezet.weebly.com/uploads/1/3/4/2/134234605/rukenelemig_balitot.pdfIn PDF document text
    • https://jumufewaxijakuk.weebly.com/uploads/1/3/1/3/131380308/6015564.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4379844/normal_600c8ad8d4d07.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4466659/normal_6051f8ab47fa7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471706/normal_600d4c43cdb1d.pdfIn PDF document text
    • https://latitatuforuza.weebly.com/uploads/1/3/1/3/131398212/mokak_tekediloka.pdfIn PDF document text
    • https://nugaginidej.weebly.com/uploads/1/3/4/4/134475369/pepafikapewatozirup.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.daltonmaag.com/In PDF document text
    • https://uploads.strikinglycdn.com/files/6ca336b1-dea3-4574-b360-34a0920ce6a4/83393434957.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9664e19e-c92e-4950-876a-23740bcd1639/granny_mod_menu_download_2020_android.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/53708d84-58de-40c1-898f-75296055fe81/71642086197.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/a86e724e-bb44-4bca-8cd9-0d90ba9a8010/guwexeduxaxogode.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/5a281e1d-9db1-49ab-a438-5f0e5fb376a1/37191424022.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b8251be1-fc31-4b75-9139-361c5123bdd6/the_art_of_color_johannes_itten_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f026a49f-1295-40a0-bc00-5e998d9130e9/how_to_reset_adora_dishwasher.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/de7942df-874c-452f-bb74-ad5f239a75ba/amazing_bible_timeline_accuracy.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000e518.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE518 5248 bytes
SHA-256: f40e37aa2b15fe9bbc567f413794d01742f193f764b96a31dbe3f6dd63ae35f1
font_01_sfnt_off0000f709.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF709 10956 bytes
SHA-256: 6af5899e45b6a80e3202329441ecbbc4f5b1d7e2dfbc4e505c580870b311e7f2
font_02_sfnt_off00011bb1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11BB1 4324 bytes
SHA-256: 1062cd8ddf90f4344fa193b395386d5669df1a952e5759311ca261a71931f361