Malicious PDF — malware analysis report

Static analysis result for SHA-256 a71b15a376401f14…

MALICIOUS

PDF

78.2 KB Created: 2021-06-09 11:23:23 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-25
MD5: ac7f996574ab3ac7f985c62b101c04f9 SHA-1: c87e76078b22283790c4ac0b0c3c827e40b9f21d SHA-256: a71b15a376401f14da708aecfd9feb12c042406baa0bd0defba798a47e175d55
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, identified as a link farm, with one prominent URL pointing to ketchas.ru. This suggests a phishing or SEO manipulation attempt. The ClamAV detection and ML classifier further support its malicious nature, classifying it as Pdf.Phishing.Trojan. No scripts were extracted, but the presence of numerous external links indicates a likely attempt to redirect users to malicious sites.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9996

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • 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://ketchas.ru/pbw?utm_term=pubg+mobile+android+ps4+controller PDF link annotation
    • https://cdn-cms.f-static.net/uploads/4382972/normal_5fd7b0c389943.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4419211/normal_606c61f0b85b8.pdfIn PDF document text
    • https://zojujevekuki.weebly.com/uploads/1/3/0/9/130969212/4365970.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4470982/normal_5fcc5bedd8415.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4480598/normal_6055bc67909e6.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4497353/normal_60337f1fae704.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4480173/normal_60062298c2d87.pdfIn PDF document text
    • https://static.s123-cdn-static.com/uploads/4478933/normal_60045450a1468.pdfIn PDF document text
    • https://zamigalimigarub.weebly.com/uploads/1/3/5/3/135326483/wosezig-pozalituruti-nebixanivotew-zivolifuzaj.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4383464/normal_602c742c3567c.pdfIn PDF document text
    • https://cdn-cms.f-static.net/uploads/4450256/normal_603da5bc5fc26.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://zefuberiwuli.pbworks.com/w/file/fetch/144845091/nigerian_military_ranks_and_symbols.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9b73305b-c506-430d-a2b9-66aa543198fb/56792777292.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/e1ec8341-111f-4971-8aa6-a7231cce6302/grade_6_math_workbook_canada.pdfIn PDF document text
    • http://xetibubib.pbworks.com/f/teddy_bear_making_patterns_free_download.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/de09f37e-78f1-4905-9d20-49f345978791/tiwuto.pdfIn PDF document text
    • http://fotowefufet.pbworks.com/w/file/fetch/144729777/fofamedoba.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/9bcedbb9-6802-4623-addb-670c6740aecc/apache_wr30m_watch_price_in_india.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/264b2000-95af-44c0-afc5-116c7f2d7ef9/does_dunkin_donuts_have_anything_keto.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/910cebea-7e81-496c-8412-ee601c39b1c2/zefititaretofezuvixobugag.pdfIn PDF document text
    • http://garigor.pbworks.com/f/donafekozaxunax.pdfIn PDF document text
    • https://uploads.strikinglycdn.com/files/dbce88d1-fdff-4dcb-98ee-fda2e0073194/35782082809.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_off0000f494.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF494 5620 bytes
SHA-256: e826098472131ef68676ac56c165a68c950109b212ad6add7c32fd42f4a082c7
font_01_sfnt_off0001079a.bin pdf-font-stream PDF embedded font (sfnt) at offset 0x1079A 10488 bytes
SHA-256: 430feed0ba02c91c2f1b7a1c232f00862923ade1bbc82582f899b6c2e7c18666