Malicious PDF — malware analysis report

Static analysis result for SHA-256 85c9a7ac255abe7b…

MALICIOUS

PDF

42.6 KB Created: 2020-07-29 23:28:07 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 4.8.7)
MD5: bd676740d1805a77bd2111e86b5fbbd9 SHA-1: 8312cd0133198b152b3c9a0c7236cf42a0b62343 SHA-256: 85c9a7ac255abe7b143a93222f542b64c4b0ecfa2aae5e0140f232f46f438184
150 Risk Score

Malware Insights

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

The PDF contains a critical heuristic firing for a malicious redirector link pointing to ttraff.com. Additionally, it exhibits a PDF link farm heuristic, with numerous links to PDFs hosted on cdn.shopify.com. The ML classifier also strongly flagged this PDF as malicious. The document body, though heavily obfuscated, contains text related to educational worksheets, suggesting a lure.

Machine Learning

  • Nyx PDF Classifier malicious score 1.0000

Heuristics 3

  • 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.
  • 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.com/wb?keyword=adding%20and%20subtracting%20fractions%20with%20unlike%20denominators%20vertical%20worksheets
    • http://files.restyle-homestaging.com/uploads/1/3/0/7/130775557/4f18c3a27a480.pdf
    • http://files.duanebrownlaw.com/uploads/1/3/1/4/131483253/2887604.pdf
    • http://files.ritaguile.com/uploads/1/3/1/1/131164174/2296247.pdf
    • http://files.gogroweducationalconsultingtutoring.com/uploads/1/3/1/0/131070894/65bc32.pdf
    • http://files.polystone.org/uploads/1/3/0/7/130739783/fakisamopinota_vedawulew.pdf
    • http://files.duanebrownlaw.com/uploads/1/3/1/4/13148325
    • https://cdn.shopify.com/s/files/1/0430/1645/4305/files/62372498297.pdf
    • https://cdn.shopify.com/s/files/1/0439/6302/3518/files/vorapim.pdf
    • https://cdn.shopify.com/s/files/1/0431/0152/0023/files/tenunisufi.pdf
    • https://cdn.shopify.com/s/files/1/0429/7375/7603/files/74316563309.pdf
    • https://cdn.shopify.com/s/files/1/0433/8234/1781/files/26738605103.pdf
    • https://cdn.shopify.com/s/files/1/0432/5956/0094/files/85657465987.pdf
    • https://cdn.shopify.com/s/files/1/0434/7012/7254/files/42016098831.pdf
    • https://cdn.shopify.com/s/files/1/0431/4667/4337/files/15553304598.pdf
    • https://cdn.shopify.com/s/files/1/0431/2779/9969/files/52375297180.pdf
    • https://cdn.shopify.com/s/files/1/0431/3025/7568/files/taromig.pdf
    • https://cdn.shopify.com/s/files/1/0428/9429/5203/files/fawatika.pdf
    • https://cdn.shopify.com/s/files/1/0434/3352/5400/files/numafajogevoregivosofevot.pdf
    • https://cdn.shopify.com/s/files/1/0427/6004/4710/files/pumovapejotikogojaza.pdf
    • https://cdn.shopify.com/s/files/1/0433/0687/7080/files/gerakofidasetivivirodipel.pdf
    • https://cdn.shopify.com/s/files/1/0429/0736/9639/files/63706529572.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_off0000671e.bin
c7a8cf7ff6bdba4701ae33a2fe3776b66ab953fa9efa33e082125030e2332fca
pdf-font-stream PDF embedded font (sfnt) at offset 0x671E 5660 bytes
font_01_sfnt_off00007a3a.bin
2482e4dfd9262b9672d2327ecd9add6f07eef3ef375c21c5f86da309a257ed22
pdf-font-stream PDF embedded font (sfnt) at offset 0x7A3A 9864 bytes