Malicious PDF — malware analysis report

Static analysis result for SHA-256 50e7e31e184d8087…

MALICIOUS

PDF

38.5 KB Created: 2020-08-17 02:37:57 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 23d2c5ef4fbaeb862971bc8374dfc6c3 SHA-1: 081eabc649aed7c4043651bc21220d567b84e13b SHA-256: 50e7e31e184d8087af924b1ed943ebe7da74c361dc878bb309ec080a147e40db
154 Risk Score

Malware Insights

MITRE ATT&CK
T1566.002 Spearphishing Attachment T1204.002 Malicious Link

The PDF contains a prominent link that redirects to a URL associated with malicious redirector infrastructure, specifically targeting a search for 'audacity 32 bit windows 7'. This suggests a social engineering tactic to trick users into downloading malware. The PDF also contains a large number of external links, many hosted on Shopify, which is characteristic of SEO link farm abuse to improve search engine ranking for malicious content. The ML classifier strongly flagged this PDF as malicious.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 4

  • PDF links to known malicious redirector infrastructure critical PDF_MALICIOUS_REDIRECTOR_LINK
    PDF contains a clickable URI to redirector infrastructure used by a known malicious PDF SEO/adware delivery campaign. These documents typically rely on user interaction and redirect chains rather than a PDF parser vulnerability.
  • 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.
  • 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://ttraff.ru/pify?keyword=audacity++32+bit+windows+7
    • http://files.firstaidcomicstaylor.com/uploads/1/3/0/9/130969489/97a4182.pdf
    • http://files.skyleblanc.com/uploads/1/3/1/6/131637034/sabosutukitikusuwiw.pdf
    • https://cdn.shopify.com/s/files/1/0433/9436/7644/files/tilting_pad_journal_bearing.pdf
    • https://cdn.shopify.com/s/files/1/0432/3108/4701/files/bivabenosawipesadugino.pdf
    • https://cdn.shopify.com/s/files/1/0432/1961/5904/files/hyrule_bass_botw.pdf
    • https://cdn.shopify.com/s/files/1/0452/0011/3813/files/daradi.pdf
    • https://cdn.shopify.com/s/files/1/0433/6405/7247/files/70525256631.pdf
    • https://cdn.shopify.com/s/files/1/0432/9691/5621/files/roleviwupo.pdf
    • https://cdn.shopify.com/s/files/1/0431/0486/2375/files/71094199857.pdf
    • https://cdn.shopify.com/s/files/1/0435/1324/9946/files/da_form_268.pdf
    • https://cdn.shopify.com/s/files/1/0435/9559/5938/files/72117459698.pdf
    • https://cdn.shopify.com/s/files/1/0438/9571/8040/files/61085152313.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000578a.bin
b583c673dab55ea8b303989f4de45afb01fc6623f7459dd329be9258d82557f3
pdf-font-stream PDF embedded font (sfnt) at offset 0x578A 5504 bytes
font_01_sfnt_off00006a6e.bin
2ceb1ab54718e5b43c9436107c5a2a72f2b719f64d255b46255f6faf2ab96be0
pdf-font-stream PDF embedded font (sfnt) at offset 0x6A6E 10360 bytes