Malicious PDF — malware analysis report

Static analysis result for SHA-256 a5a20cb1f1a06933…

MALICIOUS

PDF

83.1 KB Created: 2021-03-17 21:55:56 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 23160a04e2337fd6e9b6ed809a673315 SHA-1: a3e3718d37cac48224fb6a05058b6a03af998baa SHA-256: a5a20cb1f1a06933e726d4b1f700e1a828da1d916eaf88f1ffb87a6d04ca3dbe
184 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.001 User Execution: Malicious Link T1059.007 JavaScript

The PDF contains numerous embedded URLs, with a critical heuristic firing indicating a link to known malicious redirector infrastructure. The document body, though heavily obfuscated, suggests a lure related to 'redox potential'. The presence of multiple links hosted on disposable domains and the ML classifier's high confidence score strongly indicate a phishing or redirection attempt.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 5

  • 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 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.
  • 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://yafferge.ru/strik?utm_term=how+to+find+redox+potential In PDF document text
    • http://pshcomonhere.xyz/58138004147t745i.pdfIn PDF document text
    • http://saganofodevuset.22web.org/5216374738.pdfIn PDF document text
    • http://sovetnik53.ru/mariage_damour_piano_partitionkcllk.pdfIn PDF document text
    • http://appletopshop.ru/rubalofbgxvd.pdfIn PDF document text
    • http://sokfresh.fun/glitch_cam_pro_apk_premium_2020tw2yy.pdfIn PDF document text
    • http://pegoluzalep.22web.org/56992387139.pdfIn PDF document text
    • http://levantemosaic.com/844700512940opna.pdfIn PDF document text
    • http://kovefubiwajulo.22web.org/xozukupepobeluzun.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/08e74387-c52e-4134-8e2e-3b2b7a8ce41f/30540113040.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8cc38817-3a40-4550-8997-09fe7ea0488c/how_to_use_cen_tech_battery_charger.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/3f675216-c0ee-446d-a2f6-55d4d1501495/34700504199.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8c14ba2b-954c-41e7-957c-77ef26cd6ac2/onkyo_tx_sr705_factory_reset.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/64a45cd7-9773-4e6f-a572-2311cebbef99/68951972126.pdfIn PDF document text
    • http://gumigojozupe.epizy.com/aeronautical_engineering_colleges_in_maharashtra_list.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f2a5bd31-5182-4dea-9dd8-ee786c5b1eeb/38330714045.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/05d33f8c-0951-4bf1-ac47-83d3d4a98a13/polar_ft60_battery_replacement.pdfIn PDF document text
    • http://bugixud.epizy.com/a._b._s._t_full_form.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9e73adb2-3354-4dd4-b25c-4c6cb565ba0b/gixat.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f0483cb6-9543-4fa6-9044-f80f98b42c22/what_are_the_five_major_modes_of_action_for_antibiotics.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/8369b50d-e7be-4913-9632-dabce9554922/gigudixurenefedojuwelar.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/1c4e3987-63c9-410c-8cc3-989e3c90a280/kemebibigujubikokematok.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_off0000f8c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF8C8 4768 bytes
SHA-256: 3e9cb6fc959df796361c4b2a036fd0ee80dc1162efa90266a7f9257dc4fccb72
font_01_sfnt_off0001090c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1090C 11612 bytes
SHA-256: af4429f21cc6ce1e8e42a2f27ad52da6f498e021effbd5318179cbfe90c589b5
font_02_sfnt_off000130c8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x130C8 4324 bytes
SHA-256: 05d2457133b820fa77aa358e30e9acfbad3f04c46ced9a37296d9311117db176