Malicious PDF — malware analysis report

Static analysis result for SHA-256 c5255be055b7f38b…

MALICIOUS

PDF

37.3 KB Created: 2020-08-13 09:48:56 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: 0a9b45bee12793ce4c0dd3a27fe6ec30 SHA-1: 65c8e48e92a48c4977b5b1109f97cb58168a0adc SHA-256: c5255be055b7f38bd608065a47e29bc4d868431037ba79abacb7a56f61b8bbb3
152 Risk Score

Malware Insights

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

The PDF contains numerous embedded links, with a critical heuristic identifying a link to a known malicious redirector at 'https://ttraff.ru/pify?keyword=order+of+adjectives+worksheet+pdf+grade+5'. The document body, though partially corrupted, also contains this URL and appears to be a lure for educational content. The presence of a link farm and the ML classifier's high confidence further support the malicious nature of this document, likely intended for phishing or malware delivery.

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=order+of+adjectives+worksheet+pdf+grade+5
    • http://files.nhcss.org/uploads/1/3/1/4/131453312/2517371.pdf
    • http://files.digitalanddice.com/uploads/1/3/0/8/130874134/4398132.pdf
    • http://kenilebij.artlynchactingcoach.com/uploads/1/3/1/6/131607163/8462312.pdf
    • https://cdn.shopify.com/s/files/1/0430/6658/9335/files/gastroenteritis_dieta.pdf
    • https://cdn.shopify.com/s/files/1/0429/7123/4467/files/87183251388.pdf
    • https://cdn.shopify.com/s/files/1/0433/6313/9733/files/blue_panther_books_leseprobe.pdf
    • https://cdn.shopify.com/s/files/1/0431/3546/7669/files/sikuritasovigegano.pdf
    • https://cdn.shopify.com/s/files/1/0428/6195/3191/files/betipatowesitubag.pdf
    • https://cdn.shopify.com/s/files/1/0432/3305/0779/files/27984746067.pdf
    • https://cdn.shopify.com/s/files/1/0429/7680/5018/files/23168292829.pdf
    • https://cdn.shopify.com/s/files/1/0430/8307/1650/files/53618451649.pdf
    • https://cdn.shopify.com/s/files/1/0434/9784/8996/files/79304665594.pdf
    • https://cdn.shopify.com/s/files/1/0428/9835/8432/files/79265304831.pdf
    • https://cdn.shopify.com/s/files/1/0429/2077/1750/files/19831357372.pdf
    • https://cdn.shopify.com/s/files/1/0431/8406/2622/files/fewosexedokugapesi.pdf
    • https://cdn.shopify.com/s/files/1/0438/9843/7784/files/wojizazamazemuxinija.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_off000052b0.bin
bc4030932ad19e0fb2ca91d5509aefc9c3e1cf2243de60fbfff7f5ab8862af21
pdf-font-stream PDF embedded font (sfnt) at offset 0x52B0 5828 bytes
font_01_sfnt_off000066a5.bin
b3a26c146544142ac716193dd64cca6bf69e9a726ceecf15ef4d2c2173bdf307
pdf-font-stream PDF embedded font (sfnt) at offset 0x66A5 9852 bytes