Malicious PDF — malware analysis report

Static analysis result for SHA-256 a2c7ef0fb1d9bddf…

MALICIOUS

PDF

73.8 KB Created: 2021-02-26 15:42:13 +02:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7) First seen: 2021-11-22
MD5: a5ba1c26b81268ab3354f88d0ede6253 SHA-1: 26b999308d771035affdf07279ca115d199f8360 SHA-256: a2c7ef0fb1d9bddffeb8e3ccd64bf808f13581e5b352ea49676e177447edfdd5
186 Risk Score

Malware Insights

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

The sample is a PDF file identified as malicious by ML classifiers and ClamAV. It contains a large number of external links, many hosted on disposable domains, indicating a link farm or phishing lure. One of the extracted URLs, https://maypoin.ru/123?utm_term=navy+writing+style, is directly associated with the malicious activity. The PDF structure and heuristic firings strongly suggest an attempt to redirect users to malicious content.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9997

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://maypoin.ru/123?utm_term=navy+writing+style PDF link annotation
    • https://xegogebereduxu.weebly.com/uploads/1/3/1/1/131164392/6142678.pdfIn PDF document text
    • https://vekoduxiboba.weebly.com/uploads/1/3/1/3/131398498/69705022.pdfIn PDF document text
    • https://zuzotupewumu.weebly.com/uploads/1/3/4/6/134691050/260d0cec32a6d4f.pdfIn PDF document text
    • https://remafubununabex.weebly.com/uploads/1/3/1/4/131437283/joseliz.pdfIn PDF document text
    • https://wudowesowuzoka.weebly.com/uploads/1/3/4/5/134584143/povidetosu-fusudetoz-giganoxuluv-sixojevajo.pdfIn PDF document text
    • https://kominalekawer.weebly.com/uploads/1/3/1/6/131636772/samivus.pdfIn PDF document text
    • https://tupokigefadewun.weebly.com/uploads/1/3/4/7/134702618/zinip-tijazimukasega-gopigedasix.pdfIn PDF document text
    • http://sowopezamiw.medianewsonline.com/19248816878.pdfIn PDF document text
    • https://xuwosanilenerev.weebly.com/uploads/1/3/4/9/134900173/kegexumawon.pdfIn PDF document text
    • http://www.ascendercorp.com/In PDF document text
    • http://www.ascendercorp.com/typedesigners.htmlIn PDF document text
    • http://doriponesarom.myartsonline.com/fewepabojagewaforitivod.pdfIn PDF document text
    • https://s3.amazonaws.com/rizezobabub/14807876738.pdfIn PDF document text
    • http://kikanelomer.onlinewebshop.net/where_to_donate_office_furniture_in_chicago.pdfIn PDF document text
    • http://liroporuki.myartsonline.com/75465508425.pdfIn PDF document text
    • http://jifaradazuzigo.rf.gd/vince_gironda_8x8_workout_program.pdfIn PDF document text
    • http://luwemazezabubat.rf.gd/27844397640.pdfIn PDF document text
    • https://s3.amazonaws.com/faxaxos/99769000613.pdfIn PDF document text
    • https://s3.amazonaws.com/rizezobabub/thriller_bark_episode_guide.pdfIn PDF document text
    • http://lejopuluke.rf.gd/36604711668.pdfIn PDF document text
    • http://suvemavukefejig.epizy.com/42369584992.pdfIn PDF document text
    • https://s3.amazonaws.com/woxojuxafopuv/14876684191.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_off0000e6d1.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xE6D1 5076 bytes
SHA-256: e50479f24c90d0111384cbfbf45e193beb77de83e8a94c0cb6c5e4823b2485ea
font_01_sfnt_off0000f848.bin pdf-font-stream PDF embedded font (sfnt) at offset 0xF848 9972 bytes
SHA-256: 05b0c899c7c0eb9eb5be75e74b028e602e10104a3419cff8e4ff22eb104882dd