Malicious PDF — malware analysis report

Static analysis result for SHA-256 d88fb977cbe6f698…

MALICIOUS

PDF

98.6 KB Created: 2021-03-31 01:02:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-21
MD5: 0b4515282482c39153aefed5b7e7d156 SHA-1: be10bfd754d665c5a528652a8f8f44c2df7c9bcb SHA-256: d88fb977cbe6f6980b1cac66fc0f1ae277cd947c2b67965e74dda833b927f253
186 Risk Score

Malware Insights

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

The PDF contains a large number of external links, many hosted on disposable domains, indicating a link farm or SEO spamming operation. The ClamAV detection and ML classifier strongly suggest malicious intent, likely phishing or malware distribution. While no scripts were explicitly extracted, the PDF structure and external link farm behavior are indicative of techniques used to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9995

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://jacksth.ru/strik?utm_term=sipser+theory+of+computation+solutions+pdf PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4379613/normal_604044027cb59.pdfIn PDF document text
    • http://milatepe.medianewsonline.com/xivowutesesiludod.pdfIn PDF document text
    • http://kugaraginoja.mypressonline.com/advantages_of_mixed_economy.pdfIn PDF document text
    • https://majejuwusi.weebly.com/uploads/1/3/2/3/132303270/tofenuriw.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4491945/normal_6013723415951.pdfIn PDF document text
    • https://pefopurez.weebly.com/uploads/1/3/4/3/134375846/6403479.pdfIn PDF document text
    • https://pemilixip.weebly.com/uploads/1/3/5/3/135330450/fadafifusabu_firuv_tebegumemifina_razul.pdfIn PDF document text
    • http://dosijefa.mypressonline.com/xibetubolatil.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4466673/normal_5fe7e8a6a0021.pdfIn PDF document text
    • https://fularoxu.weebly.com/uploads/1/3/1/4/131452806/xikoxakeg.pdfIn PDF document text
    • http://zuzorovix.scienceontheweb.net/84837724446.pdfIn PDF document text
    • http://vobafoselalulor.mypressonline.com/vulakazikixejoxeju.pdfIn PDF document text
    • http://palikexifumalam.mywebcommunity.org/widow.pdfIn PDF document text
    • http://kagotigidiwijar.iblogger.org/jomilitezojogizov.pdfIn PDF document text
    • http://gigezesuzobe.getenjoyment.net/41359949336.pdfIn PDF document text
    • https://tizupimarijifik.weebly.com/uploads/1/3/1/6/131606002/db0bc799f0855c9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4496005/normal_60584ef415e2a.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4461205/normal_5ff3e164d292a.pdfIn PDF document text
    • https://kazawiluk.weebly.com/uploads/1/3/5/3/135384823/fugig_totapu_posuxu.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://www.opentle.orgIn PDF document text
    • http://wowimiberosodav.epizy.com/dixewapotoxogojimori.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://www.gnu.org/licenses/gpl.htmlIn PDF document text

Extracted artifacts 4

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000cc97.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xCC97 34360 bytes
SHA-256: 59d0d9d9c7c58efa4115f97ff87937066052f129cc75ddc3183d3ce49128c21a
font_01_sfnt_off0001367e.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1367E 5600 bytes
SHA-256: 3ffc2fcff6d0d896d4658ddf82fc819f895a86cee871b85cc0a45594a07843f7
font_02_sfnt_off0001495b.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1495B 6068 bytes
SHA-256: 58b4873d33ac9fffaf45ed1a2312b8eb5fadf3b067e77f8cfe9e87095f6a7717
font_03_sfnt_off0001590c.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1590C 10388 bytes
SHA-256: 4b1416afee92d72c4bb7d0fba24f14d839a56be0df45ea763abdabeeed655294