Malicious PDF — malware analysis report

Static analysis result for SHA-256 37a3c7e420eb6c23…

MALICIOUS

PDF

40.6 KB Created: 2020-08-12 13:23:29 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 3141e2c76783a2d99f8a8a8e43d08f55 SHA-1: 5c127bab8ab09b507208b4a1af834fdffb0532e9 SHA-256: 37a3c7e420eb6c230f29768c71a2244a3572840e4ff7a2bf2ce57c071266790c
152 Risk Score

Malware Insights

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

The PDF contains a mass external link farm, with many links pointing to Shopify domains and one primary link to a known malicious redirector. The document body text, though partially corrupted, includes the phrase 'quinolonas veterinaria pdf' and the malicious redirector URL, suggesting a lure to trick users into clicking the link. The ML classifier strongly supports the malicious nature of this PDF.

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.cc/wb?keyword=quinolonas%20veterinaria%20pdf
    • http://xarutu.stensolo.com/uploads/1/3/1/3/131383708/1583629.pdf
    • http://files.classofwestk.org/uploads/1/3/0/8/130814397/4323861.pdf
    • http://files.happysleepermattress.com/uploads/1/3/1/8/131856797/busatujomuwe.pdf
    • https://cdn.shopify.com/s/files/1/0430/5482/5621/files/44217455810.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/12247178291.pdf
    • https://cdn.shopify.com/s/files/1/0435/2265/4362/files/gupifumegaxupubere.pdf
    • https://cdn.shopify.com/s/files/1/0430/5027/0869/files/2437095551.pdf
    • https://cdn.shopify.com/s/files/1/0435/3120/6808/files/oblivion_sheet_music_piano.pdf
    • https://cdn.shopify.com/s/files/1/0436/5982/1209/files/jozasabupopujavalibubi.pdf
    • https://cdn.shopify.com/s/files/1/0429/7388/8671/files/38816417476.pdf
    • https://cdn.shopify.com/s/files/1/0435/9972/4702/files/esv_study_bible_download.pdf
    • https://cdn.shopify.com/s/files/1/0437/2021/2645/files/71681087343.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/nejoxalivivurotuzepebibus.pdf
    • https://cdn.shopify.com/s/files/1/0448/2033/2705/files/irish_bouzouki_chords_gdad.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_off00005f65.bin
c75e957aa80eac317e78fff90f88291707598b6ed4a3097bcd7e098f3bd18bbe
pdf-font-stream PDF embedded font (sfnt) at offset 0x5F65 5156 bytes
font_01_sfnt_off000070ff.bin
0615c4b71b25585e4c1ae372ae67df724bb3f1907a95fbd1d39de44add4f9a51
pdf-font-stream PDF embedded font (sfnt) at offset 0x70FF 10880 bytes