Malicious PDF — malware analysis report

Static analysis result for SHA-256 64540a520aff09d8…

MALICIOUS

PDF

78.9 KB Created: 2021-05-30 09:20:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: f924c0939e93475ef09136b5aa338af3 SHA-1: b9b91aaec99c2c364cb17db4742eb8bfce4f5891 SHA-256: 64540a520aff09d8f9c9bd3135ac159f31d80ca7a72b9d2327c8ce2e0160856b
186 Risk Score

Malware Insights

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

This PDF file was detected as malicious by ClamAV and an ML classifier. It contains a large number of external links, many pointing to disposable hosting, suggesting a link farm or SEO manipulation tactic. One of the embedded URLs, https://pelibifir.ru/strik?utm_term=what+is+maria+montessori, is likely part of the malicious infrastructure. The document body is heavily obfuscated and unreadable.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9990

Heuristics 6

  • 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
  • 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://pelibifir.ru/strik?utm_term=what+is+maria+montessori
    • https://pikotawikeju.weebly.com/uploads/1/3/4/4/134496208/4afc6ca904.pdf
    • https://cdn-cms.f-static.net/uploads/4470841/normal_60260c0a4184c.pdf
    • https://gokulibom.weebly.com/uploads/1/3/4/2/134266198/fibetunavose-ritijapape.pdf
    • https://logosomuzabi.weebly.com/uploads/1/3/0/9/130969340/3851863.pdf
    • https://moxitamun.weebly.com/uploads/1/3/4/0/134040854/346a5b807.pdf
    • https://cdn-cms.f-static.net/uploads/4465145/normal_6019c0734da27.pdf
    • https://static.s123-cdn-static.com/uploads/4465249/normal_60069ce400fea.pdf
    • https://bipixexomalexu.weebly.com/uploads/1/3/4/3/134349320/1663272.pdf
    • https://wanalupegekiful.weebly.com/uploads/1/3/4/8/134879682/8144451.pdf
    • https://pakokapixufepu.weebly.com/uploads/1/3/4/6/134659136/5041ad.pdf
    • https://figiroxofidun.weebly.com/uploads/1/3/0/7/130740151/bemuritenage.pdf
    • https://mixudepira.weebly.com/uploads/1/3/4/3/134379104/8401694.pdf
    • https://seririgikum.weebly.com/uploads/1/3/0/7/130739922/buvureme.pdf
    • https://dedotomonifagax.weebly.com/uploads/1/3/1/6/131606429/2108289.pdf
    • https://mabaxezo.weebly.com/uploads/1/3/4/7/134766945/7509258.pdf
    • https://puruvafapazono.weebly.com/uploads/1/3/0/8/130815059/9106210.pdf
    • https://static.s123-cdn-static.com/uploads/4473056/normal_5feafabfc356d.pdf
    • https://cdn-cms.f-static.net/uploads/4402740/normal_60515f95c97eb.pdf
    • https://gatodagimisosog.weebly.com/uploads/1/3/1/3/131379801/goxixufezineruna.pdf
    • http://www.ascendercorp.com/
    • http://www.ascendercorp.com/typedesigners.html
    • http://www.daltonmaag.com/
    • https://uploads.strikinglycdn.com/files/07857ecc-e97c-453c-ba56-f61cbb282bb1/skyrim_100_save_game_pc_download.pdf
    • https://uploads.strikinglycdn.com/files/961ad169-7837-4da2-9efd-cb89122a2938/nenemaxufor.pdf
    • https://uploads.strikinglycdn.com/files/b03dd8f9-59d1-4ccf-a782-5c4c42c40db8/cen_tech_5_in_1_power_pack_reviews.pdf
    • https://uploads.strikinglycdn.com/files/7e1a3849-766d-43a1-b1f3-23326e2b65ce/6821832529.pdf
    • https://uploads.strikinglycdn.com/files/299f12ea-c187-4eb5-8514-45628c59775a/87800681496.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000ece5.bin
7f68848157baceae039822472fd28fda4fbb7dc6e44efed115b8465825166a25
pdf-font-stream PDF embedded font (sfnt) at offset 0xECE5 4692 bytes
font_01_sfnt_off0000fcac.bin
5da2efa4c201ddbfc6dccc99e5180a5bf413dbe29a94d7197847f24ca84b397a
pdf-font-stream PDF embedded font (sfnt) at offset 0xFCAC 10380 bytes
font_02_sfnt_off00012027.bin
a542ec26cea93e049a2e27cd59b1347dd9bbdea13775fd7b822b3c2b3136116f
pdf-font-stream PDF embedded font (sfnt) at offset 0x12027 4324 bytes