Malicious PDF — malware analysis report

Static analysis result for SHA-256 992464c1c3d498c4…

MALICIOUS

PDF

78.8 KB Created: 2021-04-17 15:11:08 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: 81571b3bc04ee0848907ae22d325a53a SHA-1: 73549825c335c2b5a417b2e6d599ab55132e2400 SHA-256: 992464c1c3d498c425d126341513fb156d321e7c07ab034af67c5da0bde7460c
226 Risk Score

Malware Insights

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

The PDF document contains a deceptive title related to a baby's rash and embeds a large number of external links, many pointing to disposable domains and link farms. One critical heuristic identified a PDF link to an algorithmically-generated URL, and another flagged the document as a link farm on disposable hosting. The ML classifier and ClamAV detection strongly indicate malicious intent, likely for phishing or distributing further malware. No scripts were extracted, but the extensive link farm suggests a primary function of redirecting users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9998

Heuristics 7

  • 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.
  • PDF link to algorithmically-generated URL high PDF_RANDOM_URL_LINK
    PDF contains a clickable HTTP(S) link whose host looks algorithmically generated (pronounceable-random labels) and whose path/query carries a long high-entropy token. This is the randomized-redirector pattern of malspam phishing lures — the visible document is only a prompt — not 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.
  • 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://seumenha.ru/strik?utm_term=rash+on+my+baby%2527s+face PDF link annotation
    • https://static.s123-cdn-static.com/uploads/4365655/normal_60027e54b86bd.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4403689/normal_60522d959c2b9.pdfIn PDF document text
    • https://jowopuvuramikir.weebly.com/uploads/1/3/5/3/135313070/famawuv.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4370097/normal_5fdad69103c93.pdfIn PDF document text
    • https://puvugaluruwibok.weebly.com/uploads/1/3/4/4/134445294/bexuveradagiz-kewiraw-lutozup-fiwologu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4470961/normal_5fda2173de005.pdfIn PDF document text
    • http://idealicacolumbia.site/jivaxolopizemomixujomimipfpywa.pdfIn PDF document text
    • https://dimawirosaj.weebly.com/uploads/1/3/3/9/133997296/wikikofuxuve-vozuriwutukoge.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4376852/normal_601a56864c6d3.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4402247/normal_6032cfa0a559c.pdfIn PDF document text
    • https://navikeput.weebly.com/uploads/1/3/4/7/134755574/kotuxenazimuti.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4370062/normal_60013924b36d1.pdfIn PDF document text
    • https://wowajonaj.weebly.com/uploads/1/3/4/7/134717857/f4af0e81.pdfIn PDF document text
    • https://pixasarajesuwov.weebly.com/uploads/1/3/4/6/134688766/zosapumig.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4385413/normal_60663044c0271.pdfIn PDF document text
    • http://counterman.ru/new_english_words_with_meaning_in_teluguqq3st.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/3f29cade-6fed-41ae-85c7-aacf1a98ef6c/saltwater_fishing_rods_amazon.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/b4910206-3e14-47dd-a731-b96ddf81e047/neruzonuvo.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/200b22fa-7e74-4b22-99c8-c0eba5b8d9d0/16454553015.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 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000f6e6.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF6E6 5276 bytes
SHA-256: 9c03ac98e1036f7a51d6d10ef7822fd4729b65d19ed481bad76c1405e950ec07
font_01_sfnt_off000108d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x108D1 10992 bytes
SHA-256: dc3dc8a1f90c5c3b1ff22f6d6f1c56a64b1e711280aaa5e1b439854b33fd7595