Malicious PDF — malware analysis report

Static analysis result for SHA-256 acfb8dd681823774…

MALICIOUS

PDF

87.8 KB Created: 2021-03-18 04:42:10 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-09-17
MD5: 4e3064b7f032bf466c8c43d6fbcf1203 SHA-1: 33d109f6880342916766c9ef0e4ca1faceed2e33 SHA-256: acfb8dd6818237743cbe0036e5e02139c67c4a9b55afe72c14c0e656a0ff57fc
244 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1203 Exploitation for Client Execution

This PDF file was identified as malicious by multiple heuristics and a machine learning classifier. It contains a large number of embedded links, many pointing to disposable domains and redirector services, indicating a link farm designed to distribute malicious content or phish users. The ClamAV detection as 'Pdf.Phishing.Trojan' further supports this assessment.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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.
  • 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/wix?keyword=chrome+river+umn In PDF document text
    • https://cdn.sqhk.co/jedesawu/K2hizjg/sedideloxululi.pdfIn PDF document text
    • https://cdn.sqhk.co/gaxazazul/gcehdjg/catholic_full_mass_wedding_program_templates.pdfIn PDF document text
    • https://dosemawa.weebly.com/uploads/1/3/5/3/135388865/85628.pdfIn PDF document text
    • https://jetosiwer.weebly.com/uploads/1/3/4/7/134767378/difidepa.pdfIn PDF document text
    • https://zajefogana.weebly.com/uploads/1/3/1/4/131407312/23893a4a9.pdfIn PDF document text
    • https://cdn.sqhk.co/molavagew/gcWRoih/78053605760.pdfIn PDF document text
    • http://zasopawemumobaw.iblogger.org/xawafabafekexunezonigom.pdfIn PDF document text
    • http://disukikobofug.22web.org/jixesokatukagaw.pdfIn PDF document text
    • https://zebilukirun.weebly.com/uploads/1/3/5/3/135306511/1b2ac3ba5.pdfIn PDF document text
    • https://cdn.sqhk.co/pisapaxosabo/hejfhXH/46261702490.pdfIn PDF document text
    • https://fewibobukuk.weebly.com/uploads/1/3/5/3/135309281/sotofokudizetarofe.pdfIn PDF document text
    • https://cdn.sqhk.co/xazururoxe/gf2ggK4/48906588668.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • https://fad58b31-c538-4d3f-828d-7998eec853b9.filesusr.com/ugd/7e6083_05f2eeb86258401cbcd337868743ef44.pdf?index=trueIn PDF document text
    • https://c039f79f-855f-4b64-8838-30138aeea086.filesusr.com/ugd/6b78cb_2cedc96fa031478999fdc316579ad80d.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/c63c36e8-88c8-4b8f-a544-d9b9073241d6/dutch_grammar_book.pdfIn PDF document text
    • https://a134ef9b-a212-4d8e-a35f-da3d896bbd40.filesusr.com/ugd/dadc92_2b3997235bc24d70a8098df5b4c45657.pdf?index=trueIn PDF document text
    • https://uploads.strikinglycdn.com/files/fdaa8f88-4bd5-4639-bcaa-18ed5f6b0e4d/28094003816.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/2901b16b-61c0-4ec0-b754-ab2d087561b6/gufojolapuwut.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/f9364f5c-ca2c-4ce2-9b4a-24ff89deb710/how_to_start_cracked_steam_games.pdfIn PDF document text
    • https://4ef57e19-9a2e-4e6f-a444-f6b59f982a39.filesusr.com/ugd/4c1554_a4920daccc194380a1cebb1adbda551a.pdf?index=trueIn PDF document text
    • https://2489a575-72f7-492f-b117-28cfe4a4d2a3.filesusr.com/ugd/d81705_7da550badade4ddb9b66076de0a3b45f.pdf?index=trueIn 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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off00011d09.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x11D09 4468 bytes
SHA-256: 9e70bf4b65cd3a84f58fb455b9f0d55f3f24731c834ff740d56f123a58fb47d1
font_01_sfnt_off00012c0f.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12C0F 11244 bytes
SHA-256: 111e6ea319faf085a82028fa74b98fe6cd619608ba5bbff43575513e9434a11f