Malicious PDF — malware analysis report

Static analysis result for SHA-256 9a17d01ef0de6923…

MALICIOUS

PDF

83.0 KB Created: 2021-05-06 22:40:13 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: c1149737cb9e5b3141c06c156eedc929 SHA-1: da18cfd8d72ffaf060660b416027011294239eb5 SHA-256: 9a17d01ef0de69232477181ef62776904bd0c67e9caddcf8f893f7c35753f0e7
186 Risk Score

Malware Insights

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

The PDF file contains a large number of external links, many hosted on disposable domains, suggesting a link farm or phishing operation. The ML classifier and ClamAV detection strongly indicate malicious intent. The embedded URL and the document body's deceptive title 'How to write a regression analysis paper' point towards a lure to external malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

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
  • 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.
  • 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://botokaw.ru/strik?utm_term=how+to+write+a+regression+analysis+paper PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4374954/normal_5fc7f557108fd.pdfIn PDF document text
    • https://bamebifubakuta.weebly.com/uploads/1/3/1/4/131408159/9545376.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4486368/normal_6056a5da794d7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4387061/normal_602f22bdcc4cd.pdfIn PDF document text
    • http://allrecipes.pro/sedative_and_hypnotics_pptfg2ic.pdfIn PDF document text
    • http://copyrightreports.com/cmbok_4th_edition0ypod.pdfIn PDF document text
    • https://jitogomufe.weebly.com/uploads/1/3/4/5/134588764/4736221.pdfIn PDF document text
    • http://sodaapp.club/224756289792hbpn.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://855e1e5b-0daf-4dce-aa73-dfad2bfec5df.filesusr.com/ugd/ced2dc_1a9af3424b8c4db6bcd58d502a70a591.pdf?index=trueIn PDF document text
    • http://juxirijedatez.rf.gd/cracking_whip_sound.pdfIn PDF document text
    • https://50b44c92-959e-4a15-bf83-93d6b2b518d6.filesusr.com/ugd/3ed44c_6b5d2bb9551943d79e50bb9a5cbb0d02.pdf?index=trueIn PDF document text
    • https://0df22b04-17ae-4e65-9af8-3af4445b4601.filesusr.com/ugd/71fd01_ca49e3aa585e473e86cd51df93649f70.pdf?index=trueIn PDF document text
    • https://57ead060-d7b3-4f59-a803-6c9b47c0028a.filesusr.com/ugd/f30481_8632de3acffb4fd593fbf0c2dbc052ae.pdf?index=trueIn PDF document text
    • https://9cfe8934-cc69-4f76-a0d0-2e9849ea4530.filesusr.com/ugd/fd9558_5d5ec705435941eca107fc919419b01a.pdf?index=trueIn PDF document text
    • https://354df738-7a8c-4643-bdcd-aa58f7c4bd0c.filesusr.com/ugd/69cf62_97aa175e11cf4a0881e32b1e52900aa1.pdf?index=trueIn PDF document text
    • http://repuvamiperubo.epizy.com/code_light_bold_font_free.pdfIn PDF document text
    • https://dfdccaec-9019-42eb-ab8c-14eed22d5f88.filesusr.com/ugd/2e00cc_fdab556101bc43209db0b506c720b7aa.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000fbdb.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xFBDB 4932 bytes
SHA-256: 4e3e253bed34fb3d4fa4830fc3dd6da179691ebffbf2acad73679005e62df820
font_01_sfnt_off00010cb8.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x10CB8 10648 bytes
SHA-256: 35c7797819b0beabf09fabd120cc0b4b8b5bd57792400656e28e346c506cbcd8
font_02_sfnt_off00013107.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13107 4324 bytes
SHA-256: 4fcfa7c68d76e23b667942a3ac892d2d5d88346478daafc61479ad4df4af3dd3