Malicious PDF — malware analysis report

Static analysis result for SHA-256 b629e341be1a7ff4…

MALICIOUS

PDF

92.2 KB Created: 2021-06-04 15:21:55 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-24
MD5: fcf3d4fb8121f21462c371318605f091 SHA-1: 86fa1158f52890a640bd99da1463e59de1fc865b SHA-256: b629e341be1a7ff4ab476ac4e84cf5a4d95ca99a1c7d1227ec8dbf489c945b3c
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 pointing to disposable hosting services, indicating a link farm or SEO spamming operation. The ML classifier and ClamAV detection strongly suggest malicious intent, likely phishing or malware distribution. The document body, though heavily obfuscated, contains references to academic content, which is a common lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9991

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://philabc.ru/pbw?utm_term=january+2019+regents+answers+earth+science PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4473379/normal_5fd9ba9c0f7b7.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4500665/normal_5fe63493193c9.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4501996/normal_601ee4c93cb65.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4477913/normal_603ae7ee50f91.pdfIn PDF document text
    • https://mejidoxele.weebly.com/uploads/1/3/4/3/134320803/a6b80bdc.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4380229/normal_5fe8446d6c94b.pdfIn PDF document text
    • https://bejulukif.weebly.com/uploads/1/3/4/7/134746679/tijibinu.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4471946/normal_603ad3a12ff21.pdfIn PDF document text
    • https://zitifulopesere.weebly.com/uploads/1/3/4/7/134722705/refosolopi-sebul.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4503035/normal_6035966c290ec.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4377679/normal_5fed12792b70f.pdfIn PDF document text
    • https://viwoxinuzozaxa.weebly.com/uploads/1/3/1/6/131636825/kuzika.pdfIn PDF document text
    • https://medofigovur.weebly.com/uploads/1/3/5/3/135316586/ravekitulemawus_zomifazu_zuxinenoso.pdfIn PDF document text
    • https://fezuwujazu.weebly.com/uploads/1/3/5/3/135347069/pofixogumovara_xeliwo_genotonuret.pdfIn PDF document text
    • https://liganori.weebly.com/uploads/1/3/1/6/131637073/ligopef-nobexunujinaj.pdfIn PDF document text
    • https://bazapefonufoteb.weebly.com/uploads/1/3/4/6/134637130/lojalawaginasulusud.pdfIn PDF document text
    • https://zegazofegu.weebly.com/uploads/1/3/5/2/135296009/waxawoji.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4479445/normal_6033f616a27a4.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4374196/normal_6046a9877cb43.pdfIn PDF document text
    • https://kotevopokevunab.weebly.com/uploads/1/3/4/5/134590751/jupozavogo.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4371020/normal_5fe3eb14267e6.pdfIn PDF document text
    • https://kaxunuruji.weebly.com/uploads/1/3/4/7/134725802/6886562.pdfIn PDF document text
    • https://depoferi.weebly.com/uploads/1/3/4/4/134445349/rawevukepanuba_pabulirowefix_tebakopiluwub.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4445864/normal_5fcf9a3fc7716.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn 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_off00012751.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x12751 5696 bytes
SHA-256: 5917a7b80094ed5cf66a677dbd490ce308ffbe9247a16a58b2ff9a2886c9ba51
font_01_sfnt_off00013ad1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x13AD1 11704 bytes
SHA-256: 7cc59ff3c4d6022727ca7f631b6267db74541360e48855bb0cd721c48b535628