Malicious PDF — malware analysis report

Static analysis result for SHA-256 941c0a7f64ebc4d2…

MALICIOUS

PDF

82.8 KB Created: 2021-05-02 15:49:09 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-23
MD5: 3529569e9786543204a61bbad9790f32 SHA-1: 2ebecb9fb393d5a0bcc83069199c5b5143e7794e SHA-256: 941c0a7f64ebc4d2ce072d748dbdb9ff911baef39963fc80591fb4d58f8a0e1d
244 Risk Score

Malware Insights

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

This PDF file contains a large number of embedded links, many of which point to disposable hosting and are used in a link farm. One critical heuristic indicates that PDF links lead to known malicious redirector infrastructure, specifically to 'yafferge.ru'. The ML classifier and ClamAV detection strongly suggest malicious intent, likely for phishing or malware distribution via these links.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9992

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
  • 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/strik?utm_term=armitron+pro+sport+watch+instructions+set+time In PDF document text
    • https://cdn.sqhk.co/jujadiziga/5ggnjel/radio_shack_catalog_1981.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4483338/normal_605606efbe453.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4393188/normal_5fffd24c32892.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4470223/normal_60082af65aa74.pdfIn PDF document text
    • https://lulodepi.weebly.com/uploads/1/3/0/7/130776712/simukopijigonogenox.pdfIn PDF document text
    • https://kapalane.weebly.com/uploads/1/3/0/9/130968981/9459996.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4405651/normal_6006978124fc7.pdfIn PDF document text
    • https://nunavataregexo.weebly.com/uploads/1/3/0/7/130775742/b5027.pdfIn PDF document text
    • https://cdn.sqhk.co/tisufupujeli/gGia8ij/99678336457.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4450424/normal_5fee3179ab089.pdfIn PDF document text
    • https://miriziwu.weebly.com/uploads/1/3/0/7/130774981/6821307.pdfIn PDF document text
    • https://cdn.sqhk.co/ruxuvedije/gchcYhc/28413662482.pdfIn PDF document text
    • https://cdn.sqhk.co/toxaxiked/eEgfjf6/city_racing_3d_multiplayer_mod_apk_download.pdfIn PDF document text
    • https://kemebawe.weebly.com/uploads/1/3/5/3/135313751/4701875.pdfIn PDF document text
    • https://xoravali.weebly.com/uploads/1/3/0/7/130775395/bivifuwusifa_bikor_kowaka_topad.pdfIn PDF document text
    • https://juguzitusiketi.weebly.com/uploads/1/3/4/3/134372303/11c685a5215.pdfIn PDF document text
    • https://xezixopizanew.weebly.com/uploads/1/3/5/3/135314636/botom_rejetolomuka_loxegetedasune.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/411200d3-d590-4b11-9041-bdef56a434a2/is_there_going_to_be_a_sequel_to_allegiant.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/40f62a40-b86b-4a90-88ec-61bec34af3cd/legunumenodekezerezakatop.pdfIn PDF document text
    • https://44bb6ee8-a0fe-4f72-890f-0f0a2fec05cf.filesusr.com/ugd/b65acf_365d6e737c80482f9274bf473d43bf03.pdf?index=trueIn PDF document text
    • https://36071b1a-d853-4ad1-bccf-0ed894d94038.filesusr.com/ugd/906e9f_3cfb3ad7d1bf4f04a67b94b046c4c066.pdf?index=trueIn PDF document text
    • https://94aa8f26-b07a-4c24-bdb4-4112657565c9.filesusr.com/ugd/37428b_289970e4f85c444d9310dbda5c3647f8.pdf?index=trueIn PDF document text
    • https://f039f7e9-c7fa-441d-bf3d-2f0e35d6be10.filesusr.com/ugd/80685d_005fa3f6d8884fbba35a009041148c7b.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_off00010641.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10641 5224 bytes
SHA-256: 0e5a06d27b03440c2fc198529db0356f1f357e2570733737f61a642ba250d825
font_01_sfnt_off000117e8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x117E8 10956 bytes
SHA-256: 4b10bb3deca98cb8491550a22ce6af994cc1b1822ce908f76cf963076ef601c2