Malicious PDF — malware analysis report

Static analysis result for SHA-256 b3b28421c3830dda…

MALICIOUS

PDF

87.9 KB Created: 2021-03-23 04:27:42 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-14
MD5: 43e666948befb6783f382737ab1b7afa SHA-1: d7c64839bc8ee41b782b905d167de37bd540f8c6 SHA-256: b3b28421c3830dda3978f0e453aa122780d99065d16d6ab212c016d1ba84f56d
262 Risk Score

Malware Insights

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

The PDF contains heuristics indicating it is a malicious redirector and part of an SEO link farm, specifically targeting invoice-related keywords. The embedded URL https://dafemum.ru/123?utm_term=invoice+payment+terms+template+uk is flagged as malicious. While no scripts were explicitly extracted, the PDF structure and malicious links suggest an attempt to redirect users to a phishing or malware distribution site, aligning with a spearphishing attachment tactic.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 7

  • 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.
  • Fake invoice / payment lure low SE_INVOICE_LURE
    Document contains invoice or payment language paired with an action verb — useful context when combined with link, macro, or attachment indicators
  • 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/123?utm_term=invoice+payment+terms+template+uk In PDF document text
    • https://cdn.sqhk.co/vozofugova/z2icGYo/waves_tune_real_time_vs_logic_pro_x.pdfIn PDF document text
    • http://lnstagram-copyright-confirms.com/77744292045c5cw.pdfIn PDF document text
    • https://dobivevoxopu.weebly.com/uploads/1/3/1/4/131453544/5683722.pdfIn PDF document text
    • https://cdn.sqhk.co/saligoliti/axjdieC/54509722549.pdfIn PDF document text
    • https://welavomuwaj.weebly.com/uploads/1/3/4/6/134633166/5d06bbb604d49f.pdfIn PDF document text
    • https://fidojosamesevuf.weebly.com/uploads/1/3/4/5/134594598/luparisuzod.pdfIn PDF document text
    • http://naturebiolog.fun/azur_lane_fleet_guide_2019i0t3o.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://uploads.strikinglycdn.com/files/9b496ab5-6dc2-4fc7-b7c4-cd0102542655/37228357509.pdfIn PDF document text
    • https://s3.amazonaws.com/fovezewi/halo_astro_a50_manual.pdfIn PDF document text
    • https://s3.amazonaws.com/luropiw/roland_keyboard_d50_price_in_bangladesh.pdfIn PDF document text
    • https://s3.amazonaws.com/wezukep/how_to_write_an_equation_in_slope_intercept_form_calculator.pdfIn PDF document text
    • https://s3.amazonaws.com/gozifep/american_harvest_snackmaster_dehydrator_2400_manual.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8b3d28ba-986e-403a-b8bf-e0f411527f6a/is_tefl_certification_hard.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/7e272116-13a7-45c6-988d-d9862187b08e/which_is_more_dangerous_sociopath_or_psychopath.pdfIn PDF document text
    • https://s3.amazonaws.com/tudawufed/elite_dangerous_ps4_cheat_sheet.pdfIn PDF document text
    • https://s3.amazonaws.com/divelatoxa/38518759908.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/745d5397-220a-4a85-87e5-9bf75006ceb4/tukonenexibudubuxaki.pdfIn PDF document text
    • https://s3.amazonaws.com/bupesejirijejus/coming_soon_website_template_html5_free.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/22e85089-27ae-4efe-98f6-b70a67ba7d6a/blendtec_total_blender_classic_with_wildside_jar.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
    • http://dejavu.sourceforge.netIn PDF document text
    • http://dejavu.sourceforge.net/wiki/index.php/LicenseIn PDF document text

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0001042d.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1042D 5244 bytes
SHA-256: c79ed400fce72be40a83a24bb9d1f2b7dfff9641812fafeb7999df1fc32c1916
font_01_sfnt_off000115f9.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x115F9 11380 bytes
SHA-256: 0e4df6888b2a3fb074dab316af8d4832995808f71ee2ee32a1c0687cac71f0b1
font_02_sfnt_off00013ccd.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13CCD 16144 bytes
SHA-256: f6e0f4a25f18a144688c6b7f40519a5efc98c72643b9054f89526e396d9b459d