Malicious PDF — malware analysis report

Static analysis result for SHA-256 53dc843a148c744e…

MALICIOUS

PDF

55.2 KB Created: 2020-07-29 15:16:45 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: d8272545fd51d804204943782ae98665 SHA-1: 0a1567b1071db4313f9378dd5f7a601a0a7e3f13 SHA-256: 53dc843a148c744ea7e5208e13354a3c32e6ace823643eeac6ad6360f90e9279
152 Risk Score

Malware Insights

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

The PDF file contains a large number of embedded links, identified as a link farm. One of these links, 'https://ttraff.cc/pify?keyword=bucket+sort+algorithm+pdf', points to known malicious redirector infrastructure. The document body, though heavily obfuscated, suggests a lure related to 'bucket sort algorithm pdf'. The ML classifier also strongly indicated maliciousness.

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/pify?keyword=bucket+sort+algorithm+pdf
    • http://files.annaschneiderdesigns.com/uploads/1/3/0/7/130775729/8238955.pdf
    • http://files.christopherenston.org/uploads/1/3/1/3/131379219/xoxewijexidukasa.pdf
    • http://files.hollybrookchurch.com/uploads/1/3/1/3/131398278/6736245.pdf
    • http://files.lauderdalecountymsarchives.org/uploads/1/3/0/7/130738903/towolujikenanatesi.pdf
    • http://files.msdooleysscienceclass.com/uploads/1/3/1/4/131407214/nigapabebedawo.pdf
    • http://files.lauderdalecountymsarchives.or
    • https://cdn.shopify.com/s/files/1/0433/0553/3604/files/bamusa.pdf
    • https://cdn.shopify.com/s/files/1/0433/4898/3959/files/59906402808.pdf
    • https://cdn.shopify.com/s/files/1/0433/3830/1594/files/41360125126.pdf
    • https://cdn.shopify.com/s/files/1/0434/3431/1845/files/3130667587.pdf
    • https://cdn.shopify.com/s/files/1/0430/8588/9689/files/midumefamikenefaw.pdf
    • https://cdn.shopify.com/s/files/1/0431/4506/8699/files/juzajomafe.pdf
    • https://cdn.shopify.com/s/files/1/0428/0962/2687/files/46099733318.pdf
    • https://cdn.shopify.com/s/files/1/0434/4528/9127/files/89227628098.pdf
    • https://cdn.shopify.com/s/files/1/0440/2541/3782/files/24031011522.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 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000797c.bin
85cfe15f0c7ec589690cdda31066a566e1c53de994122ce12813169ed4b26801
pdf-font-stream PDF embedded font (sfnt) at offset 0x797C 5460 bytes
font_01_sfnt_off00008c16.bin
d7e90ea2b54189dffdc5dfa51376b58b1fd2ed714e4d7bdcbbd8476f3fb2747f
pdf-font-stream PDF embedded font (sfnt) at offset 0x8C16 14816 bytes
font_02_sfnt_off0000bab1.bin
fe122861e8158e69f770b537b34ebcea90de60b8d6f6493873744392b7767c47
pdf-font-stream PDF embedded font (sfnt) at offset 0xBAB1 16064 bytes